[PATCH v5 0/3] USB/UVC: Add quirks to prevent Razer Kiyo Pro xHCI cascade failure

[PATCH v5 0/3] USB/UVC: Add quirks to prevent Razer Kiyo Pro xHCI cascade failure

[JP Hein]

The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has a
well-documented failure mode that cascades into complete xHCI host
controller death, disconnecting every USB device on the bus -- including
keyboards and mice, requiring a hard reboot.

The device has two crash triggers:

  1. LPM/autosuspend resume: Device enters LPM or autosuspend, fails to
     reinitialize on resume, producing EPIPE (-32) on UVC SET_CUR. The
     stalled endpoint triggers an xHCI stop-endpoint timeout, and the
     kernel declares the host controller dead.

  2. Rapid control transfers: sustained rapid UVC SET_CUR operations
     (hundreds over several seconds) overwhelm the firmware. The error-code query
     (GET_CUR on UVC_VC_REQUEST_ERROR_CODE_CONTROL) amplifies the
     failure by sending a second transfer to the already-stalling device,
     pushing it into a full lockup and xHCI controller death.

This has been reported as Ubuntu Launchpad Bug #2061177, with reports
across kernel versions 6.5 through 6.8.

This series adds three patches:

Patch 1: USB core -- USB_QUIRK_NO_LPM to prevent Link Power Management
  transitions that destabilize the device firmware.

Patch 2: UVC driver -- introduce UVC_QUIRK_CTRL_THROTTLE to rate-limit
  SET_CUR control transfers (50ms minimum interval) and skip the
  error-code query after EPIPE errors on affected devices.

Patch 3: UVC driver -- add Razer Kiyo Pro device table entry with
  UVC_QUIRK_CTRL_THROTTLE, UVC_QUIRK_DISABLE_AUTOSUSPEND, and
  UVC_QUIRK_NO_RESET_RESUME to address both crash triggers.

Together, these keep the device in a stable active state, prevent rapid
control transfer crashes, and avoid the power management transitions
that trigger the firmware bug.

Testing on 6.17.0-19-generic (Ubuntu 24.04 HWE) with dynamic debug
enabled and NO patches or workarounds applied:
  - v4l2-ctl stress test (control transfers only): passes 50/50
  - Starting a video call: triggers hc_died() via LPM disable failure
    during isochronous stream setup
  - Stress test during active video call: firmware stalls at round 19,
    repeated endpoint stalls with -32 EPIPE

The 6.8 -> 6.17 xHCI error handling improvements help with control
transfer recovery, but the firmware lockup during video streaming still
cascades to hc_died(). The patches in this series prevent the firmware
from reaching the lockup state in the first place.

Changes since v4:
  - Dropped stable CC (new quirks, not regression fixes)
  - Updated cover letter with 6.17 test results

Changes since v3:
  - Regenerated patches against media-committers next branch to fix
    context mismatch (v3 was based on Ubuntu 6.8 source)

Tested on:
  - Kernel: 6.17.0-19-generic (Ubuntu 24.04 HWE) and 6.8.0-106-generic
  - Hardware: Intel Cannon Lake PCH xHCI (8086:a36d)
  - Device: Razer Kiyo Pro (1532:0e05), firmware 1.5.0.1

Stress test, crash evidence, and debug logs:
  https://github.com/jphein/kiyo-xhci-fix

JP Hein (3):
  USB: core: add NO_LPM quirk for Razer Kiyo Pro webcam
  media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware
  media: uvcvideo: add quirks for Razer Kiyo Pro webcam

 drivers/media/usb/uvc/uvc_driver.c | 17 ++++++++++++++++
 drivers/media/usb/uvc/uvc_video.c  | 32 ++++++++++++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h   |  3 +++
 drivers/usb/core/quirks.c          |  2 ++
 4 files changed, 54 insertions(+)

[PATCH v5 1/3] USB: core: add NO_LPM quirk for Razer Kiyo Pro webcam

[JP Hein]

The Razer Kiyo Pro (1532:0e05) is a USB 3.0 UVC webcam whose firmware
does not handle USB Link Power Management transitions reliably. When LPM
is active, the device can enter a state where it fails to respond to
control transfers, producing EPIPE (-32) errors on UVC probe control
SET_CUR requests. In the worst case, the stalled endpoint triggers an
xHCI stop-endpoint command that times out, causing the host controller
to be declared dead and every USB device on the bus to be disconnected.

This has been reported as Ubuntu Launchpad Bug #2061177. The failure
mode is:

  1. UVC probe control SET_CUR returns -32 (EPIPE)
  2. xHCI host not responding to stop endpoint command
  3. xHCI host controller not responding, assume dead
  4. All USB devices on the affected xHCI controller disconnect

Disabling LPM prevents the firmware from entering the problematic low-
power states that precede the stall. This is the same approach used for
other webcams with similar firmware issues (e.g., Logitech HD Webcam C270).

Cc: stable@vger.kernel.org
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2061177
Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/usb/core/quirks.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 9e7e49712..7c4038a1e 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -480,6 +480,8 @@ static const struct usb_device_id usb_quirk_list[] = {
 	/* Razer - Razer Blade Keyboard */
 	{ USB_DEVICE(0x1532, 0x0116), .driver_info =
 			USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL },
+	/* Razer - Razer Kiyo Pro Webcam */
+	{ USB_DEVICE(0x1532, 0x0e05), .driver_info = USB_QUIRK_NO_LPM },
 
 	/* Lenovo ThinkPad OneLink+ Dock twin hub controllers (VIA Labs VL812) */
 	{ USB_DEVICE(0x17ef, 0x1018), .driver_info = USB_QUIRK_RESET_RESUME },
-- 
2.43.0

[PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[JP Hein]

Some USB webcams have firmware that crashes when it receives rapid
consecutive UVC control transfers (SET_CUR). The Razer Kiyo Pro
(1532:0e05) is one such device -- after several hundred rapid control
changes over a few seconds, the device stops responding entirely,
triggering an xHCI stop-endpoint command timeout that causes the host
controller to be declared dead, disconnecting every USB device on the
bus.

The failure is amplified by the standard UVC error-code query: when a
SET_CUR fails with EPIPE, the driver sends a second transfer (GET_CUR
on UVC_VC_REQUEST_ERROR_CODE_CONTROL) to read the UVC error code. On a
device that is already stalling, this second transfer pushes the
firmware into a full lockup.

Introduce UVC_QUIRK_CTRL_THROTTLE (0x00080000) to address both issues:

  - Enforce a minimum 50ms interval between SET_CUR control transfers,
    preventing the rapid-fire pattern that overwhelms the firmware.
    50ms allows up to 20 control changes per second, which is sufficient
    for interactive slider adjustments while keeping the device stable.

  - Skip the UVC_VC_REQUEST_ERROR_CODE_CONTROL query after EPIPE errors
    on devices with this quirk. EPIPE is returned directly without the
    follow-up query that would amplify the failure.

The UVC control path is serialized by ctrl_mutex, so last_ctrl_set_jiffies
does not require additional locking.

Cc: stable@vger.kernel.org
Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_video.c | 32 +++++++++++++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h  |  3 +++
 2 files changed, 35 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 40c76c051..9f402f55e 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -75,8 +75,30 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	u8 error;
 	u8 tmp;
 
+	/*
+	 * Rate-limit SET_CUR operations for devices with fragile firmware.
+	 * The Razer Kiyo Pro locks up under sustained rapid SET_CUR
+	 * transfers (hundreds without delay), crashing the xHCI controller.
+	 */
+	if (query == UVC_SET_CUR &&
+	    (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)) {
+		unsigned long min_interval = msecs_to_jiffies(50);
+
+		if (dev->last_ctrl_set_jiffies &&
+		    time_before(jiffies,
+				dev->last_ctrl_set_jiffies + min_interval)) {
+			unsigned long elapsed = dev->last_ctrl_set_jiffies +
+						min_interval - jiffies;
+			msleep(jiffies_to_msecs(elapsed));
+		}
+	}
+
 	ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
 				UVC_CTRL_CONTROL_TIMEOUT);
+
+	if (query == UVC_SET_CUR &&
+	    (dev->quirks & UVC_QUIRK_CTRL_THROTTLE))
+		dev->last_ctrl_set_jiffies = jiffies;
 	if (likely(ret == size))
 		return 0;
 
@@ -108,6 +130,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 		return ret < 0 ? ret : -EPIPE;
 	}
 
+	/*
+	 * Skip the error code query for devices that crash under load.
+	 * The standard error-code query (GET_CUR on
+	 * UVC_VC_REQUEST_ERROR_CODE_CONTROL) sends a second USB transfer to
+	 * a device that is already stalling, which can amplify the failure
+	 * into a full firmware lockup and xHCI controller death.
+	 */
+	if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)
+		return -EPIPE;
+
 	/* Reuse data[0] to request the error code. */
 	tmp = *(u8 *)data;
 
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 8480d65ec..cafc71457 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -81,6 +81,7 @@
 #define UVC_QUIRK_INVALID_DEVICE_SOF	0x00010000
 #define UVC_QUIRK_MJPEG_NO_EOF		0x00020000
 #define UVC_QUIRK_MSXU_META		0x00040000
+#define UVC_QUIRK_CTRL_THROTTLE		0x00080000
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED		0x00000001
@@ -579,6 +580,8 @@ struct uvc_device {
 	struct usb_interface *intf;
 	unsigned long warnings;
 	u32 quirks;
+	/* Control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
+	unsigned long last_ctrl_set_jiffies;
 	int intfnum;
 	char name[32];
 
-- 
2.43.0

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Ricardo Ribalda]

Hi JP

On Tue, 31 Mar 2026 at 02:38, JP Hein <jp@jphein.com> wrote:
>
> Some USB webcams have firmware that crashes when it receives rapid
> consecutive UVC control transfers (SET_CUR). The Razer Kiyo Pro
> (1532:0e05) is one such device -- after several hundred rapid control
> changes over a few seconds, the device stops responding entirely,
> triggering an xHCI stop-endpoint command timeout that causes the host
> controller to be declared dead, disconnecting every USB device on the
> bus.

A usb device shall not be able crash the whole USB host. I believe
that you already captured some logs and the USB guys are looking into
it. I'd really like to hear what they have to say after reviewing
them.

>
> The failure is amplified by the standard UVC error-code query: when a
> SET_CUR fails with EPIPE, the driver sends a second transfer (GET_CUR
> on UVC_VC_REQUEST_ERROR_CODE_CONTROL) to read the UVC error code. On a
> device that is already stalling, this second transfer pushes the
> firmware into a full lockup.
>
> Introduce UVC_QUIRK_CTRL_THROTTLE (0x00080000) to address both issues:
>
>   - Enforce a minimum 50ms interval between SET_CUR control transfers,
>     preventing the rapid-fire pattern that overwhelms the firmware.
>     50ms allows up to 20 control changes per second, which is sufficient
>     for interactive slider adjustments while keeping the device stable.
>
>   - Skip the UVC_VC_REQUEST_ERROR_CODE_CONTROL query after EPIPE errors
>     on devices with this quirk. EPIPE is returned directly without the
>     follow-up query that would amplify the failure.
>
> The UVC control path is serialized by ctrl_mutex, so last_ctrl_set_jiffies
> does not require additional locking.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: JP Hein <jp@jphein.com>
> ---
>  drivers/media/usb/uvc/uvc_video.c | 32 +++++++++++++++++++++++++++++++
>  drivers/media/usb/uvc/uvcvideo.h  |  3 +++
>  2 files changed, 35 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index 40c76c051..9f402f55e 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -75,8 +75,30 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>         u8 error;
>         u8 tmp;
>

Why don't do you do the rate-limit in __uvc_query_ctrl()?

Are you sure that you only have to limit UVC_SET_CUR?

> +       /*
> +        * Rate-limit SET_CUR operations for devices with fragile firmware.
> +        * The Razer Kiyo Pro locks up under sustained rapid SET_CUR
> +        * transfers (hundreds without delay), crashing the xHCI controller.
> +        */
> +       if (query == UVC_SET_CUR &&
> +           (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)) {
> +               unsigned long min_interval = msecs_to_jiffies(50);
> +
> +               if (dev->last_ctrl_set_jiffies &&
> +                   time_before(jiffies,
> +                               dev->last_ctrl_set_jiffies + min_interval)) {
> +                       unsigned long elapsed = dev->last_ctrl_set_jiffies +
> +                                               min_interval - jiffies;
> +                       msleep(jiffies_to_msecs(elapsed));
> +               }
> +       }
> +
>         ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
>                                 UVC_CTRL_CONTROL_TIMEOUT);
> +
> +       if (query == UVC_SET_CUR &&
> +           (dev->quirks & UVC_QUIRK_CTRL_THROTTLE))
> +               dev->last_ctrl_set_jiffies = jiffies;
>         if (likely(ret == size))
>                 return 0;
>
> @@ -108,6 +130,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>                 return ret < 0 ? ret : -EPIPE;
>         }
>
> +       /*
> +        * Skip the error code query for devices that crash under load.
> +        * The standard error-code query (GET_CUR on
> +        * UVC_VC_REQUEST_ERROR_CODE_CONTROL) sends a second USB transfer to
> +        * a device that is already stalling, which can amplify the failure
> +        * into a full firmware lockup and xHCI controller death.
> +        */
> +       if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)
> +               return -EPIPE;
> +
>         /* Reuse data[0] to request the error code. */
>         tmp = *(u8 *)data;
>
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 8480d65ec..cafc71457 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -81,6 +81,7 @@
>  #define UVC_QUIRK_INVALID_DEVICE_SOF   0x00010000
>  #define UVC_QUIRK_MJPEG_NO_EOF         0x00020000
>  #define UVC_QUIRK_MSXU_META            0x00040000
> +#define UVC_QUIRK_CTRL_THROTTLE                0x00080000
>
>  /* Format flags */
>  #define UVC_FMT_FLAG_COMPRESSED                0x00000001
> @@ -579,6 +580,8 @@ struct uvc_device {
>         struct usb_interface *intf;
>         unsigned long warnings;
>         u32 quirks;
> +       /* Control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
> +       unsigned long last_ctrl_set_jiffies;
>         int intfnum;
>         char name[32];
>
> --
> 2.43.0
>


-- 
Ricardo Ribalda

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Jeffrey Hein]

Hi Ricardo,

On Thu, 9 Apr 2026 at 08:45, Ricardo Ribalda <ribalda@chromium.org> wrote:
> A usb device shall not be able crash the whole USB host. I believe
> that you already captured some logs and the USB guys are looking into
> it. I'd really like to hear what they have to say after reviewing
> them.

Agreed -- a single device shouldn't be able to take down the host.
Alan Stern raised the same point and asked whether xhci-hcd should
handle this. Michal Pecio noted that the stop-endpoint command timeout
is a controller-side failure and asked for dynamic debug traces on
newer kernels and non-Intel hardware.

I provided the 6.17 traces. The result: the stress test (control
transfers only) now passes 50/50 thanks to xHCI error handling
improvements between 6.8 and 6.17. But starting a video stream still
triggers hc_died() -- the firmware fails to disable LPM during stream
setup, the endpoint stalls, and the stop-endpoint command times out.

So there's an open question on the xHCI side about whether the
controller could recover from stop-endpoint timeouts instead of
killing the HC. The UVC quirks are defense-in-depth -- they prevent
the firmware from reaching the failure state that triggers the timeout
in the first place.

I'm also planning to test on additional Intel machines (and non-Intel
if I can source one) to determine whether the stop-endpoint timeout
is controller-specific, per Michal's request.

> Why don't do you do the rate-limit in __uvc_query_ctrl()?

Good point -- moved it there in v6. This covers all callers including
uvc_set_video_ctrl() which bypasses uvc_query_ctrl() for probe/commit.

> Are you sure that you only have to limit UVC_SET_CUR?

I haven't been able to isolate the crash to a specific query direction
-- our testing shows it's the sustained transfer rate that matters. v6
throttles all query types in __uvc_query_ctrl() to be safe.

v6 posted with these changes.

Thanks,
JP

>
> On Wed, Apr 8, 2026 at 11:45 PM Ricardo Ribalda <ribalda@chromium.org> wrote:
>>
>> Hi JP
>>
>> On Tue, 31 Mar 2026 at 02:38, JP Hein <jp@jphein.com> wrote:
>> >
>> > Some USB webcams have firmware that crashes when it receives rapid
>> > consecutive UVC control transfers (SET_CUR). The Razer Kiyo Pro
>> > (1532:0e05) is one such device -- after several hundred rapid control
>> > changes over a few seconds, the device stops responding entirely,
>> > triggering an xHCI stop-endpoint command timeout that causes the host
>> > controller to be declared dead, disconnecting every USB device on the
>> > bus.
>>
>> A usb device shall not be able crash the whole USB host. I believe
>> that you already captured some logs and the USB guys are looking into
>> it. I'd really like to hear what they have to say after reviewing
>> them.
>>
>> >
>> > The failure is amplified by the standard UVC error-code query: when a
>> > SET_CUR fails with EPIPE, the driver sends a second transfer (GET_CUR
>> > on UVC_VC_REQUEST_ERROR_CODE_CONTROL) to read the UVC error code. On a
>> > device that is already stalling, this second transfer pushes the
>> > firmware into a full lockup.
>> >
>> > Introduce UVC_QUIRK_CTRL_THROTTLE (0x00080000) to address both issues:
>> >
>> >   - Enforce a minimum 50ms interval between SET_CUR control transfers,
>> >     preventing the rapid-fire pattern that overwhelms the firmware.
>> >     50ms allows up to 20 control changes per second, which is sufficient
>> >     for interactive slider adjustments while keeping the device stable.
>> >
>> >   - Skip the UVC_VC_REQUEST_ERROR_CODE_CONTROL query after EPIPE errors
>> >     on devices with this quirk. EPIPE is returned directly without the
>> >     follow-up query that would amplify the failure.
>> >
>> > The UVC control path is serialized by ctrl_mutex, so last_ctrl_set_jiffies
>> > does not require additional locking.
>> >
>> > Cc: stable@vger.kernel.org
>> > Signed-off-by: JP Hein <jp@jphein.com>
>> > ---
>> >  drivers/media/usb/uvc/uvc_video.c | 32 +++++++++++++++++++++++++++++++
>> >  drivers/media/usb/uvc/uvcvideo.h  |  3 +++
>> >  2 files changed, 35 insertions(+)
>> >
>> > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
>> > index 40c76c051..9f402f55e 100644
>> > --- a/drivers/media/usb/uvc/uvc_video.c
>> > +++ b/drivers/media/usb/uvc/uvc_video.c
>> > @@ -75,8 +75,30 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>> >         u8 error;
>> >         u8 tmp;
>> >
>>
>> Why don't do you do the rate-limit in __uvc_query_ctrl()?
>>
>> Are you sure that you only have to limit UVC_SET_CUR?
>>
>> > +       /*
>> > +        * Rate-limit SET_CUR operations for devices with fragile firmware.
>> > +        * The Razer Kiyo Pro locks up under sustained rapid SET_CUR
>> > +        * transfers (hundreds without delay), crashing the xHCI controller.
>> > +        */
>> > +       if (query == UVC_SET_CUR &&
>> > +           (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)) {
>> > +               unsigned long min_interval = msecs_to_jiffies(50);
>> > +
>> > +               if (dev->last_ctrl_set_jiffies &&
>> > +                   time_before(jiffies,
>> > +                               dev->last_ctrl_set_jiffies + min_interval)) {
>> > +                       unsigned long elapsed = dev->last_ctrl_set_jiffies +
>> > +                                               min_interval - jiffies;
>> > +                       msleep(jiffies_to_msecs(elapsed));
>> > +               }
>> > +       }
>> > +
>> >         ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
>> >                                 UVC_CTRL_CONTROL_TIMEOUT);
>> > +
>> > +       if (query == UVC_SET_CUR &&
>> > +           (dev->quirks & UVC_QUIRK_CTRL_THROTTLE))
>> > +               dev->last_ctrl_set_jiffies = jiffies;
>> >         if (likely(ret == size))
>> >                 return 0;
>> >
>> > @@ -108,6 +130,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>> >                 return ret < 0 ? ret : -EPIPE;
>> >         }
>> >
>> > +       /*
>> > +        * Skip the error code query for devices that crash under load.
>> > +        * The standard error-code query (GET_CUR on
>> > +        * UVC_VC_REQUEST_ERROR_CODE_CONTROL) sends a second USB transfer to
>> > +        * a device that is already stalling, which can amplify the failure
>> > +        * into a full firmware lockup and xHCI controller death.
>> > +        */
>> > +       if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)
>> > +               return -EPIPE;
>> > +
>> >         /* Reuse data[0] to request the error code. */
>> >         tmp = *(u8 *)data;
>> >
>> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
>> > index 8480d65ec..cafc71457 100644
>> > --- a/drivers/media/usb/uvc/uvcvideo.h
>> > +++ b/drivers/media/usb/uvc/uvcvideo.h
>> > @@ -81,6 +81,7 @@
>> >  #define UVC_QUIRK_INVALID_DEVICE_SOF   0x00010000
>> >  #define UVC_QUIRK_MJPEG_NO_EOF         0x00020000
>> >  #define UVC_QUIRK_MSXU_META            0x00040000
>> > +#define UVC_QUIRK_CTRL_THROTTLE                0x00080000
>> >
>> >  /* Format flags */
>> >  #define UVC_FMT_FLAG_COMPRESSED                0x00000001
>> > @@ -579,6 +580,8 @@ struct uvc_device {
>> >         struct usb_interface *intf;
>> >         unsigned long warnings;
>> >         u32 quirks;
>> > +       /* Control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
>> > +       unsigned long last_ctrl_set_jiffies;
>> >         int intfnum;
>> >         char name[32];
>> >
>> > --
>> > 2.43.0
>> >
>>
>>
>> --
>> Ricardo Ribalda

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

On Thu, 9 Apr 2026 08:45:17 +0200, Ricardo Ribalda wrote:
> Hi JP
> 
> On Tue, 31 Mar 2026 at 02:38, JP Hein <jp@jphein.com> wrote:
> >
> > Some USB webcams have firmware that crashes when it receives rapid
> > consecutive UVC control transfers (SET_CUR). The Razer Kiyo Pro
> > (1532:0e05) is one such device -- after several hundred rapid
> > control changes over a few seconds, the device stops responding
> > entirely, triggering an xHCI stop-endpoint command timeout that
> > causes the host controller to be declared dead, disconnecting every
> > USB device on the bus.  
> 
> A usb device shall not be able crash the whole USB host. I believe
> that you already captured some logs and the USB guys are looking into
> it. I'd really like to hear what they have to say after reviewing
> them.

Sorry, I forgot about this bug. I will take a closer look at logs
later today.

I see that there is a case which crashes the host controller, but
without dynamic debug. It would be helpful if this can be reproduced
with debug enabled.

In the future, please also make sure that there are no unrelated
devices spamming dmesg, like "slot 17 ep 2" in those "stall" logs.
Please find this device and disconnect it or unbind its driver.

The initial cause of all that may really be the device getting
locked up for no good reason, but not 100% sure yet.

Regards,
Michal

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Jeffrey Hein]

Hi Michal,

Thanks for taking another look.

I will reproduce the hc_died() crash with dynamic debug enabled
(xhci_hcd +p, usbcore +p) and with all unrelated USB devices
disconnected so the logs are clean. The slot 17 stalls in the
previous logs may have been from another device on the bus --
I will make sure only the Kiyo is connected for the next capture.

The crash that kills the controller happens when starting a video
stream (LPM disable failure path). I can SSH in to grab dmesg
live during the crash since the controller death only takes out
USB, not the network.

Will follow up with the traces.

Thanks,
JP


On Thu, Apr 9, 2026 at 1:02 AM Michal Pecio <michal.pecio@gmail.com> wrote:
>
> On Thu, 9 Apr 2026 08:45:17 +0200, Ricardo Ribalda wrote:
> > Hi JP
> >
> > On Tue, 31 Mar 2026 at 02:38, JP Hein <jp@jphein.com> wrote:
> > >
> > > Some USB webcams have firmware that crashes when it receives rapid
> > > consecutive UVC control transfers (SET_CUR). The Razer Kiyo Pro
> > > (1532:0e05) is one such device -- after several hundred rapid
> > > control changes over a few seconds, the device stops responding
> > > entirely, triggering an xHCI stop-endpoint command timeout that
> > > causes the host controller to be declared dead, disconnecting every
> > > USB device on the bus.
> >
> > A usb device shall not be able crash the whole USB host. I believe
> > that you already captured some logs and the USB guys are looking into
> > it. I'd really like to hear what they have to say after reviewing
> > them.
>
> Sorry, I forgot about this bug. I will take a closer look at logs
> later today.
>
> I see that there is a case which crashes the host controller, but
> without dynamic debug. It would be helpful if this can be reproduced
> with debug enabled.
>
> In the future, please also make sure that there are no unrelated
> devices spamming dmesg, like "slot 17 ep 2" in those "stall" logs.
> Please find this device and disconnect it or unbind its driver.
>
> The initial cause of all that may really be the device getting
> locked up for no good reason, but not 100% sure yet.
>
> Regards,
> Michal

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

On Thu, 9 Apr 2026 10:02:47 +0200, Michal Pecio wrote:
> On Thu, 9 Apr 2026 08:45:17 +0200, Ricardo Ribalda wrote:
> > A usb device shall not be able crash the whole USB host. I believe
> > that you already captured some logs and the USB guys are looking
> > into it. I'd really like to hear what they have to say after
> > reviewing them.
> 
> Sorry, I forgot about this bug. I will take a closer look at logs
> later today.

lsusb -v of identical(?) device is found here:
http://linux-hardware.org/?probe=a1cd74d9ac&log=lsusb

And I'm looking at the logs here:
https://github.com/jphein/kiyo-xhci-fix/tree/main/kernel-patches/crash-evidence

crash-6.17-stock-stress-20260330.log
Empty file, not sure why included at all.

crash-6.17-video-call-20260330.log
No debug messages. At some point:
Mar 30 10:00:52 katana kernel: usb 2-3.4: disable of device-initiated U1 failed.
Mar 30 10:00:53 katana kernel: usb 2-3.4: Failed to set U2 timeout to 0x0,error code -110
Mar 30 10:00:53 katana kernel: uvcvideo 2-3.4:1.1: usb_set_interface Failed to disable LPM
Mar 30 10:00:54 katana kernel: usb 2-3.4: Failed to query (SET_CUR) UVC control 11 on unit 3: -71 (exp. 1).
Mar 30 10:00:54 katana kernel: usb 2-3.4: Failed to query (SET_CUR) UVC control 11 on unit 3: -71 (exp. 1).
Mar 30 10:00:54 katana kernel: usb 2-3.4: Failed to query (SET_CUR) UVC control 11 on unit 3: -71 (exp. 1).

Not sure if the LPM thing is the cause or a symptom of general EP 0
disfunction, as seen in subsequent EPROTO errors.

Not sure why usb_set_interface() is called. Is this the start streaming
case mentioned in some email? What was happening before?

stall-6.17-stock-no-workarounds-20260330.log
All sorts of repeating errors, including stall on EP1IN ("ep 2") which
is supposedly isochronous and shouldn't. Clearly some broken state, not
sure how things got there.

stall-6.17-stress-during-call-20260330.log
This is the most interesting one.

The first slightly unusual thing is repeated unlinks on EP5IN (int),
not sure why uvcvideo would do that, possibly result of the stess test.
I know that such pattern alone can break ASMedia host controllers for
no reason I understand, though this one is Intel.

It's suspicious that wBytesPerInterval of the endpoint is 8, wMaxPacket
is 64 and URBs are 16 bytes. Just in case, I attach a test patch which
rises wBytesPerInterval to match wMaxPacketSize.

The first definite anomaly is Transaction Error on EP5IN:
Mar 30 16:59:16 katana kernel: xhci_hcd 0000:00:14.0: Transfer error for slot 18 ep 10 on endpoint
Mar 30 16:59:16 katana kernel: xhci_hcd 0000:00:14.0: Hard-reset ep 10, slot 18

Not sure why endpoint reset follows immediately without retries.
The test patch also removes one potential reason. We might see whether
the retries will fail, or if retrying until the transfer succeeds
magically prevents the subsequent disaster. Perhaps the device gets
unusually upset about sequence mismatch on this endpoint, which results
from not clearing this halt condition properly (known problem).

Five seconds later two control URBs are unlinked:
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 00000000122aa5e2, dev 3.1, ep 0x0, starting at offset 0x11e227b40
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: // Ding dong!
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 000000008a55bcd3, dev 3.1, ep 0x0, starting at offset 0x11e227b20
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Not queuing Stop Endpoint on slot 18 ep 0 in state 0x44

Probably timeout, i.e. things got stuck. Oddly, state 0x44 indicates
that this control endpoint has previously halted - error or stall.

Higher layers notice that things are timing out:

Mar 30 16:59:21 katana kernel: usb 2-3.1: pipewire timed out on ep0out len=0/0
Mar 30 16:59:21 katana kernel: usb 2-3.1: disable of device-initiated U1 failed.
Mar 30 16:59:21 katana kernel: usb 2-3.1: ThreadPoolSingl timed out on ep0out len=0/1

Nothing works from now. At some point the parent hub reports
disconnection and reconnection. Still nothing works.

---

Would it be possible to repeat this test with the patch below?
It overrides the suspicious wBytesPerInterval and hopefully enables
retries of this failed interrupt URB. We will see what happens.

xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 1d50c91afd7f..17d78b4e07bf 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1464,6 +1464,10 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	mult = xhci_get_endpoint_mult(xhci, udev, ep);
 	max_packet = xhci_usb_endpoint_maxp(udev, ep);
 	max_burst = xhci_get_endpoint_max_burst(udev, ep);
+	if (interval && max_esit_payload < max_packet) {
+		xhci_err(xhci, "max_esit_payload %d -> %d\n", max_esit_payload, max_packet);
+		max_esit_payload = max_packet;
+	}
 	avg_trb_len = max_esit_payload;
 
 	/* FIXME dig Mult and streams info out of ep companion desc */
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 98ef014c8dee..e5823650850a 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2544,6 +2544,7 @@ static void process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 		td->status = 0;
 		break;
 	case COMP_SHORT_PACKET:
+		ep->err_count = 0;
 		td->status = 0;
 		break;
 	case COMP_STOPPED_SHORT_PACKET:

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Jeffrey Hein]

Hi Michal,

Thanks for the detailed analysis.

> crash-6.17-stock-stress-20260330.log
> Empty file, not sure why included at all.

Sorry about that -- removed.

> Not sure why usb_set_interface() is called. Is this the start
> streaming case mentioned in some email? What was happening before?

Yes, this is the start-streaming path. The app (Google Meet via
browser) opens the video device, which triggers usb_set_interface()
to select the alt setting for the isochronous endpoint. The LPM
disable failure happens during that transition.

> It's suspicious that wBytesPerInterval of the endpoint is 8,
> wMaxPacket is 64 and URBs are 16 bytes.

Interesting find. I had not looked at the interrupt endpoint
descriptors closely.

> Would it be possible to repeat this test with the patch below?

Absolutely. I will apply your patch, rebuild xhci-hcd, reproduce
the crash with dynamic debug enabled (xhci_hcd +p, usbcore +p),
only the Kiyo connected, and grab dmesg via SSH during the crash.

The CI bot flagged a dts-bindings failure on v6 but all code checks
(compile, smatch, sparse, checkpatch) passed -- unrelated to the
UVC patches.

Will follow up with traces.

Thanks,
JP



On Thu, Apr 9, 2026 at 1:17 PM Michal Pecio <michal.pecio@gmail.com> wrote:
>
> On Thu, 9 Apr 2026 10:02:47 +0200, Michal Pecio wrote:
> > On Thu, 9 Apr 2026 08:45:17 +0200, Ricardo Ribalda wrote:
> > > A usb device shall not be able crash the whole USB host. I believe
> > > that you already captured some logs and the USB guys are looking
> > > into it. I'd really like to hear what they have to say after
> > > reviewing them.
> >
> > Sorry, I forgot about this bug. I will take a closer look at logs
> > later today.
>
> lsusb -v of identical(?) device is found here:
> http://linux-hardware.org/?probe=a1cd74d9ac&log=lsusb
>
> And I'm looking at the logs here:
> https://github.com/jphein/kiyo-xhci-fix/tree/main/kernel-patches/crash-evidence
>
> crash-6.17-stock-stress-20260330.log
> Empty file, not sure why included at all.
>
> crash-6.17-video-call-20260330.log
> No debug messages. At some point:
> Mar 30 10:00:52 katana kernel: usb 2-3.4: disable of device-initiated U1 failed.
> Mar 30 10:00:53 katana kernel: usb 2-3.4: Failed to set U2 timeout to 0x0,error code -110
> Mar 30 10:00:53 katana kernel: uvcvideo 2-3.4:1.1: usb_set_interface Failed to disable LPM
> Mar 30 10:00:54 katana kernel: usb 2-3.4: Failed to query (SET_CUR) UVC control 11 on unit 3: -71 (exp. 1).
> Mar 30 10:00:54 katana kernel: usb 2-3.4: Failed to query (SET_CUR) UVC control 11 on unit 3: -71 (exp. 1).
> Mar 30 10:00:54 katana kernel: usb 2-3.4: Failed to query (SET_CUR) UVC control 11 on unit 3: -71 (exp. 1).
>
> Not sure if the LPM thing is the cause or a symptom of general EP 0
> disfunction, as seen in subsequent EPROTO errors.
>
> Not sure why usb_set_interface() is called. Is this the start streaming
> case mentioned in some email? What was happening before?
>
> stall-6.17-stock-no-workarounds-20260330.log
> All sorts of repeating errors, including stall on EP1IN ("ep 2") which
> is supposedly isochronous and shouldn't. Clearly some broken state, not
> sure how things got there.
>
> stall-6.17-stress-during-call-20260330.log
> This is the most interesting one.
>
> The first slightly unusual thing is repeated unlinks on EP5IN (int),
> not sure why uvcvideo would do that, possibly result of the stess test.
> I know that such pattern alone can break ASMedia host controllers for
> no reason I understand, though this one is Intel.
>
> It's suspicious that wBytesPerInterval of the endpoint is 8, wMaxPacket
> is 64 and URBs are 16 bytes. Just in case, I attach a test patch which
> rises wBytesPerInterval to match wMaxPacketSize.
>
> The first definite anomaly is Transaction Error on EP5IN:
> Mar 30 16:59:16 katana kernel: xhci_hcd 0000:00:14.0: Transfer error for slot 18 ep 10 on endpoint
> Mar 30 16:59:16 katana kernel: xhci_hcd 0000:00:14.0: Hard-reset ep 10, slot 18
>
> Not sure why endpoint reset follows immediately without retries.
> The test patch also removes one potential reason. We might see whether
> the retries will fail, or if retrying until the transfer succeeds
> magically prevents the subsequent disaster. Perhaps the device gets
> unusually upset about sequence mismatch on this endpoint, which results
> from not clearing this halt condition properly (known problem).
>
> Five seconds later two control URBs are unlinked:
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 00000000122aa5e2, dev 3.1, ep 0x0, starting at offset 0x11e227b40
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: // Ding dong!
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 000000008a55bcd3, dev 3.1, ep 0x0, starting at offset 0x11e227b20
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Not queuing Stop Endpoint on slot 18 ep 0 in state 0x44
>
> Probably timeout, i.e. things got stuck. Oddly, state 0x44 indicates
> that this control endpoint has previously halted - error or stall.
>
> Higher layers notice that things are timing out:
>
> Mar 30 16:59:21 katana kernel: usb 2-3.1: pipewire timed out on ep0out len=0/0
> Mar 30 16:59:21 katana kernel: usb 2-3.1: disable of device-initiated U1 failed.
> Mar 30 16:59:21 katana kernel: usb 2-3.1: ThreadPoolSingl timed out on ep0out len=0/1
>
> Nothing works from now. At some point the parent hub reports
> disconnection and reconnection. Still nothing works.
>
> ---
>
> Would it be possible to repeat this test with the patch below?
> It overrides the suspicious wBytesPerInterval and hopefully enables
> retries of this failed interrupt URB. We will see what happens.
>
> xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index 1d50c91afd7f..17d78b4e07bf 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -1464,6 +1464,10 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
>         mult = xhci_get_endpoint_mult(xhci, udev, ep);
>         max_packet = xhci_usb_endpoint_maxp(udev, ep);
>         max_burst = xhci_get_endpoint_max_burst(udev, ep);
> +       if (interval && max_esit_payload < max_packet) {
> +               xhci_err(xhci, "max_esit_payload %d -> %d\n", max_esit_payload, max_packet);
> +               max_esit_payload = max_packet;
> +       }
>         avg_trb_len = max_esit_payload;
>
>         /* FIXME dig Mult and streams info out of ep companion desc */
> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
> index 98ef014c8dee..e5823650850a 100644
> --- a/drivers/usb/host/xhci-ring.c
> +++ b/drivers/usb/host/xhci-ring.c
> @@ -2544,6 +2544,7 @@ static void process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
>                 td->status = 0;
>                 break;
>         case COMP_SHORT_PACKET:
> +               ep->err_count = 0;
>                 td->status = 0;
>                 break;
>         case COMP_STOPPED_SHORT_PACKET:
>
>
>
>

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Jeffrey Hein]

One more thing -- you mentioned referencing an lsusb from
linux-hardware.org for an "identical(?) device". Here is the actual
lsusb -vv from our device, confirming the wBytesPerInterval mismatch
you found.

EP5 IN (interrupt) from raw SS Endpoint Companion descriptor:

  Endpoint Descriptor:
    bEndpointAddress     0x85  EP 5 IN
    bmAttributes            3  (Interrupt)
    wMaxPacketSize     0x0040  1x 64 bytes
    bInterval               8
  SS Endpoint Companion:
    bMaxBurst               0
    bmAttributes         0x00
    wBytesPerInterval       8

So wBytesPerInterval (8) is indeed 8x smaller than wMaxPacketSize (64),
matching what you saw in the third-party listing.

Note that lsusb -vv does not decode wBytesPerInterval for this
endpoint -- the value above was parsed from the raw descriptor bytes
in sysfs. The full lsusb -vv (934 lines) is now in the repo:

    https://github.com/jphein/kiyo-xhci-fix/blob/main/kernel-patches/crash-evidence/lsusb-vv-kiyo-pro.txt

I will follow up with the test results from your patch.

JP

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

On Thu, 9 Apr 2026 17:24:36 -0700, Jeffrey Hein wrote:
> So wBytesPerInterval (8) is indeed 8x smaller than wMaxPacketSize
> (64), matching what you saw in the third-party listing.

Technically it's a spec violation if a device claims 8 bytes but
respons with a single packet larger than that to a 16 byte (or any
other) URB. Though no problems were known to result until last month.
It seems most host controllers ignore byte per interval on interrupt.

> Note that lsusb -vv does not decode wBytesPerInterval for this
> endpoint -- the value above was parsed from the raw descriptor bytes
> in sysfs. The full lsusb -vv (934 lines) is now in the repo:

It does decode it, but you need the latest usbutils version 019.

And there should be no need for lsusb -vv, just lsusb -v.
I think the output pasted into v6 patch was truncated.

Regards,
Michal

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Mathias Nyman]

On 4/9/26 23:17, Michal Pecio wrote:

> Five seconds later two control URBs are unlinked:
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 00000000122aa5e2, dev 3.1, ep 0x0, starting at offset 0x11e227b40
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: // Ding dong!
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 000000008a55bcd3, dev 3.1, ep 0x0, starting at offset 0x11e227b20
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Not queuing Stop Endpoint on slot 18 ep 0 in state 0x44

log continues with:
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x11e227b40 (dma) in stream 0 URB 00000000122aa5e2
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x11e227b20 (dma) in stream 0 URB 000000008a55bcd3
Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x11e227b40, cycle 0

One theory could be that xHC control endpoint refuses to restart when its dequeue
pointer is moved to a no-op TD like in this case (second cancelled URB).

xhci spec section 4.8.3 'Endpoint context state' additional Note states that:
"The Default Control Endpoint shall return to the Running state when the
  Doorbell is rung for the next Setup Stage TD sent to the endpoint."

Here the dequeue pointer will still be on the no-op TRB after queuing a new
control transfer after it. Not on a setup stage TRB

This can happen when we cancel two control URBs at the same time.
We turn the second URB TRBs starting at 0x11e227b40 into no-ops,
then move past the first URB TRBs starting at 0x11e227b20 to the second URB no-op TRB
at 0x11e227b40.

It's possible that disabling LPM helps as it reduces the number of control transfers,
so there is a much smaller risk of cancelling two control URBs in one go.

Thanks
Mathias

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Jeffrey Hein]

On Sat, 11 Apr 2026 00:48:05 +0300, Mathias Nyman wrote:
> One theory could be that xHC control endpoint refuses to restart when its
> dequeue pointer is moved to a no-op TD like in this case (second cancelled
> URB).
>
> This can happen when we cancel two control URBs at the same time.

I tested Michal's xhci patch (max_esit_payload clamp + short packet
err_count reset) on a custom 6.17.0 kernel. Two separate tests below.

Hardware: Intel Cannon Lake PCH xHCI (8086:a36d)
Device: Razer Kiyo Pro (1532:0e05), bcdDevice 8.21
Kernel: 6.17.0-xhci-test (vanilla 6.17 + Michal's patch)

max_esit_payload 8 -> 64 confirmed firing at boot for EP5IN.

Test 1: Michal's xhci patch + JP's UVC patches + NO_LPM
=========================================================
Active: usbcore.quirks=1532:0e05:k (NO_LPM), DKMS uvcvideo with
UVC_QUIRK_CTRL_THROTTLE, Michal's xhci patch.

Result: HC died. The crash sequence from the full log:

1) 437 repeated Cancel/resubmit cycles on EP5 IN (ep 0x85, slot 5
   ep 10) over ~7 minutes starting mid-call:

  [15:18:58] Cancel URB 0000000028356cb5, dev 3.1, ep 0x85, starting
at offset 0x114a49080
  [15:18:58] Stopped on Transfer TRB for slot 5 ep 10
  ... (437 cancel/resubmit cycles through 15:26:04)

   This is the same "repeated unlinks on EP5IN" pattern you noted in
   the March 30 stall-6.17-stress-during-call log, Michal.

2) After the last ep 0x85 cancellation + endpoint reconfigure (add
   ep 0x81), ~994,000 spurious SHORT_PACKET events (comp_code 13)
   flooded the HC for ~5 minutes:

  [15:26:04] add ep 0x81, slot id 5
  [15:26:04] Successful Endpoint Configure command
  [15:26:04] Spurious event dma ..., comp_code 13 after 13
  ... (~993,703 spurious events through 15:30:48)

3) Control transfers started timing out, with miss service interval
   errors on isochronous eps 2 and 4:

  [15:30:48] Cancel URB ..., dev 3.1, ep 0x0
  [15:30:53] Cancel URB ..., dev 3.1, ep 0x0  (5s stop-ep timeout)
  [15:30:53] ThreadPoolSingl timed out on ep0in len=0/2
  [15:30:53] Failed to query (GET_CUR) UVC control 6 on unit 1: -110
  [15:30:59] Cancel URB ..., dev 3.1, ep 0x0
  [15:31:04] Command timeout, USBSTS: 0x00000000
  [15:31:04] xHCI host controller not responding, assume dead

Full log (2.9MB gz, 1.06M lines):
https://github.com/jphein/kiyo-xhci-fix/blob/main/kernel-patches/crash-evidence/crash-6.17.0-xhci-test-20260410-152541.log.gz

Test 2: Michal's xhci patch ONLY (clean isolation)
====================================================
Active: ONLY Michal's xhci patch. No usbcore.quirks cmdline, stock
uvcvideo (DKMS module disabled), LPM and autosuspend at defaults.

Result: HC survived.

Video call ran successfully. Then ran stress test (rapid v4l2-ctl
control transfers -- focus, white balance, exposure, zoom, brightness
cycling). Firmware locked at round ~23:

  [336.489500] usb 2-3.1: pipewire timed out on ep0out len=0/0
  [336.489503] usb 2-3.1: disable of device-initiated U1 failed.
  [336.489510] usb 2-3.1: v4l2-ctl timed out on ep0out len=0/8
  [336.504055] Transfer error for slot 36 ep 10 on endpoint
  ... (repeating timeout/error cycle every ~5s)

Device firmware was completely unresponsive, but the host controller
survived. No hc_died(). The transfer errors were on ep 10 (EP5 IN,
the endpoint Michal's patch targeted).

Full log (1.2MB gz):
https://github.com/jphein/kiyo-xhci-fix/blob/main/kernel-patches/crash-evidence/crash-6.17.0-xhci-test-20260410-154243.log.gz

Full dmesg:
https://github.com/jphein/kiyo-xhci-fix/blob/main/kernel-patches/crash-evidence/michal-only-stress-20260410.log

Summary
========
In both tests, EP5 IN (interrupt, wBytesPerInterval=8) was at the
center of the problem. In Test 1, the repeated unlinks on EP5 IN
led to a spurious event flood that eventually killed the HC. In
Test 2, EP5 IN had transfer errors but the HC handled them without
dying.

The key variable between the tests was the UVC throttle and NO_LPM,
not Michal's xhci patch (which was active in both). I don't yet
understand why the additional UVC-layer mitigations would make the
HC outcome worse, not better. Different test conditions (stream
teardown in Test 1 vs active streaming in Test 2) may explain it.

Michal, re: lsusb -- I built usbutils 019 from source and confirmed
it decodes wBytesPerInterval natively:

      Endpoint Descriptor:
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            3
          Transfer Type            Interrupt
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               8
        bMaxBurst               0
        wBytesPerInterval       8

Full lsusb -v (usbutils 019, 927 lines):
https://github.com/jphein/kiyo-xhci-fix/blob/main/kernel-patches/crash-evidence/lsusb-v-kiyo-pro-usbutils019.txt

v7 patch 2/2 included lsusb -vv (934 lines). If lsusb -v is preferred
I can swap it in a v8.

I have other Intel machines available for testing if you'd like to
confirm this isn't Cannon Lake-specific. No AMD hardware currently.

JP

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

On Fri, 10 Apr 2026 16:06:43 -0700, Jeffrey Hein wrote:
> Test 1: Michal's xhci patch + JP's UVC patches + NO_LPM
> =========================================================
> Active: usbcore.quirks=1532:0e05:k (NO_LPM), DKMS uvcvideo with
> UVC_QUIRK_CTRL_THROTTLE, Michal's xhci patch.
> 
> Result: HC died. The crash sequence from the full log:
> 
> 1) 437 repeated Cancel/resubmit cycles on EP5 IN (ep 0x85, slot 5
>    ep 10) over ~7 minutes starting mid-call:
> 
>   [15:18:58] Cancel URB 0000000028356cb5, dev 3.1, ep 0x85, starting
> at offset 0x114a49080
>   [15:18:58] Stopped on Transfer TRB for slot 5 ep 10
>   ... (437 cancel/resubmit cycles through 15:26:04)
> 
>    This is the same "repeated unlinks on EP5IN" pattern you noted in
>    the March 30 stall-6.17-stress-during-call log, Michal.
> 
> 2) After the last ep 0x85 cancellation + endpoint reconfigure (add
>    ep 0x81), ~994,000 spurious SHORT_PACKET events (comp_code 13)
>    flooded the HC for ~5 minutes:
> 
>   [15:26:04] add ep 0x81, slot id 5
>   [15:26:04] Successful Endpoint Configure command
>   [15:26:04] Spurious event dma ..., comp_code 13 after 13

That's not abnormal and it probably shouldn't be logged at all.
I filtered out some of this noise from subsequent log snippets.

This is interesting because it shows the isochronous video endpoint
being enabled and then stopped and removed shortly after:

[Fri Apr 10 15:26:04 2026] xhci_hcd 0000:00:14.0: add ep 0x81, slot id 5, new drop flags = 0x0, new add flags = 0x8
[Fri Apr 10 15:26:04 2026] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev 00000000921e7e25
[Fri Apr 10 15:26:04 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:26:04 2026] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[Fri Apr 10 15:26:05 2026] xhci_hcd 0000:00:14.0: Cancel URB 0000000009b97440, dev 3.1, ep 0x81, starting at offset 0x2db0885f0
[Fri Apr 10 15:26:05 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:26:05 2026] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 5 ep 2
[...]
[Fri Apr 10 15:26:05 2026] xhci_hcd 0000:00:14.0: drop ep 0x81, slot id 5, new drop flags = 0x8, new add flags = 0x0

Then EP5IN submit/unlink cycles continue.
And video starts again:

[Fri Apr 10 15:26:09 2026] xhci_hcd 0000:00:14.0: add ep 0x81, slot id 5, new drop flags = 0x0, new add flags = 0x8
[Fri Apr 10 15:26:09 2026] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev 00000000921e7e25
[Fri Apr 10 15:26:09 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:26:09 2026] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command

Transfer error followed by normal operation, seems harmless so far:

[Fri Apr 10 15:29:04 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 5 ep 2 on endpoint
[Fri Apr 10 15:29:04 2026] xhci_hcd 0000:00:14.0: Error mid isoc TD, wait for final completion event
[Fri Apr 10 15:29:04 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 5 ep 2 on endpoint
[Fri Apr 10 15:29:04 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fb7e0, comp_code 13 after 13

EP0 stall, not seen before. A bit suspicious, but video still runs:

[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x00000002db088de0, comp_code 13 after 13
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x00000002db088e10, comp_code 13 after 13
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Stalled endpoint for slot 5 ep 0
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Hard-reset ep 0, slot 5
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Ignoring reset ep completion code of 1
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x114a485c0 (dma) in stream 0 URB 000000000ffbecf4
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x114a485f0, cycle 0
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: xhci_giveback_invalidated_tds: Keep cancelled URB 000000000ffbecf4 TD as cancel_status is 2
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x00000002db088e40, comp_code 13 after 13
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq = @114a485f0
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: xhci_handle_cmd_set_deq: Giveback cancelled URB 000000000ffbecf4 TD
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Giveback URB 000000000ffbecf4, len = 0, expected = 4, status = -32
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: xhci_handle_cmd_set_deq: All TDs cleared, ring doorbell
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x00000002db088e80, comp_code 13 after 13
[Fri Apr 10 15:30:26 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x00000002db088eb0, comp_code 13 after 13

EP0 timeout and unlink, video endpoint fails shortly after:

[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbe30, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbe60, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Cancel URB 0000000008ead041, dev 3.1, ep 0x0, starting at offset 0x114a48290
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 5 ep 0
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x114a48290 (dma) in stream 0 URB 0000000008ead041
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x114a482c0, cycle 0
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: xhci_giveback_invalidated_tds: Keep cancelled URB 0000000008ead041 TD as cancel_status is 2
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq = @114a482c0
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: xhci_handle_cmd_set_deq: Giveback cancelled URB 0000000008ead041 TD
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Giveback URB 0000000008ead041, len = 2, expected = 2, status = -115
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: xhci_handle_cmd_set_deq: All TDs cleared, ring doorbell
[Fri Apr 10 15:30:48 2026] usb 2-3.1: ThreadPoolSingl timed out on ep0in len=2/2
[Fri Apr 10 15:30:48 2026] usb 2-3.1: Failed to query (GET_CUR) UVC control 6 on unit 1: -110 (exp. 2).
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbe90, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbec0, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbef0, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbf30, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x000000028c6fbf60, comp_code 13 after 13
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 5 ep 2 on endpoint
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Miss service interval error for slot 5 ep 2, set skip flag
[Fri Apr 10 15:30:48 2026] xhci_hcd 0000:00:14.0: Miss service interval error for slot 5 ep 2, set skip flag

Now things are properly broken. Next EP0 URB times out too:

[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Cancel URB 000000008f70ed5c, dev 3.1, ep 0x0, starting at offset 0x114a482c0
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x114a482f0, cycle 0
[...]
[Fri Apr 10 15:30:53 2026] usb 2-3.1: ThreadPoolSingl timed out on ep0in len=0/2
[Fri Apr 10 15:30:53 2026] usb 2-3.1: Failed to query (GET_CUR) UVC control 6 on unit 1: -110 (exp. 2).

Fololwed by Transaction Error on the next and subsequent ones:

[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 5 ep 0 on endpoint
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: TRB error 4, halted endpoint index = 0
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Hard-reset ep 0, slot 5
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Ignoring reset ep completion code of 1
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x114a482f0 (dma) in stream 0 URB 000000000ca6398c
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x114a48320, cycle 0
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: xhci_giveback_invalidated_tds: Keep cancelled URB 000000000ca6398c TD as cancel_status is 2
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Successful Set TR Deq Ptr cmd, deq = @114a48320
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: xhci_handle_cmd_set_deq: Giveback cancelled URB 000000000ca6398c TD
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: Giveback URB 000000000ca6398c, len = 0, expected = 2, status = -71
[Fri Apr 10 15:30:53 2026] xhci_hcd 0000:00:14.0: xhci_handle_cmd_set_deq: All TDs cleared, ring doorbell
[Fri Apr 10 15:30:53 2026] usb 2-3.1: Failed to query (GET_CUR) UVC control 6 on unit 1: -71 (exp. 2).

It seems the driver stopped resubmitting video URBs here and issued
some control transfer. It timed out and unlinking crashed the HC.

[Fri Apr 10 15:30:54 2026] xhci_hcd 0000:00:14.0: Miss service interval error for slot 5 ep 2, set skip flag
[Fri Apr 10 15:30:54 2026] xhci_hcd 0000:00:14.0: Miss service interval error for slot 5 ep 2, set skip flag
[Fri Apr 10 15:30:54 2026] xhci_hcd 0000:00:14.0: Overrun event on slot 5 ep 2
[Fri Apr 10 15:30:54 2026] xhci_hcd 0000:00:14.0: Skipped one TD for slot 5 ep 2
[Fri Apr 10 15:30:59 2026] xhci_hcd 0000:00:14.0: Cancel URB 000000007f4f069a, dev 3.1, ep 0x0, starting at offset 0x114a48770
[Fri Apr 10 15:30:59 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:31:04 2026] xhci_hcd 0000:00:14.0: Command timeout, USBSTS: 0x00000000
[Fri Apr 10 15:31:04 2026] xhci_hcd 0000:00:14.0: xHCI host not responding to stop endpoint command

---

Question: can you kill it by starting some video application to set the
camera up, closing it and then running this loop?

while :; do v4l2-ctl -d /dev/video0 --stream-mmap --stream-count=1; done

Regards,
Michal

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

[-- Attachment #1: Type: text/plain, Size: 1189 bytes --]

On Mon, 13 Apr 2026 10:05:45 +0200, Michal Pecio wrote:
> Question: can you kill it by starting some video application to set
> the camera up, closing it and then running this loop?
> 
> while :; do v4l2-ctl -d /dev/video0 --stream-mmap --stream-count=1; done

Hi again,

Any chance you could try it? And also the attached test program:

cc -lusb-1.0 hammerint.c -o hammerint
sudo ./hammerint 1532 0e05 0 85

Initial arguments are VID:PID of the device, next is the number of
an interface containing some interrupt endpoint and then the endpoint
address (including 8_ if IN).

I tried with a variety of SuperSpeed devices (UVC, NICs, hubs) and this
reliably breaks ASMedia HCs within seconds. If the same is the case on
Intel then it's a bigger problem than just UVC.

The video streaming loop breaks even more controllers. I have some
general idea how the streaming case could be dealt with, but not so
much the interrupt one. Maybe rate limiting. I found that avoiding
Set TR Dequeue to Link TRBs reduces failure rate, but not to zero.

Long ago I also looked at the issued command sequences and I haven't
noticed obvious errors or spec violations. Looks like a HW bug.

Regards,
Michal

[-- Attachment #2: hammerint.c --]
[-- Type: text/x-c++src, Size: 1425 bytes --]

#include <stdio.h>
#include <stdlib.h>

#include <libusb-1.0/libusb.h>

void comp(struct libusb_transfer *t) {
	char c = t->status == LIBUSB_TRANSFER_CANCELLED ? '.' :
		t->status == LIBUSB_TRANSFER_COMPLETED ? ',' : '-';
	fputc(c, stdout);
	fflush(stdout);
}

int hammer(int vid, int pid, int ifc, int ep) {
	struct libusb_device_handle *d;
	struct libusb_transfer *t;
	char bufi[1024] = {0};
	char bufc[2];
	int r;

	r = libusb_init(NULL);
	t = libusb_alloc_transfer(0);
	if (r || !t)
		return 1;

	d = libusb_open_device_with_vid_pid(NULL, vid, pid);
	if (!d)
		return 2;

	libusb_detach_kernel_driver(d, ifc);
	r = libusb_claim_interface(d, ifc);
	if (r)
		return 3;

	libusb_fill_interrupt_transfer(t, d, ep, bufi, sizeof(bufi), comp, NULL, 0);

	for (;;) {
		/* GET_STATUS(DEVICE) */
		r = libusb_control_transfer(d, 0x80, 0, 0, 0, bufc, sizeof(bufc), 100);
		if (r != sizeof(bufc))
			return 4;

		r = libusb_submit_transfer(t);
		if (r)
			return 5;
		r = libusb_cancel_transfer(t);
		if (r)
			return 6;
		r = libusb_handle_events(NULL);
		if (r)
			return 7;
	}
}

int main (int argc, char **argv) {
	int vid, pid, ifc, ep;
	int r;

	if (argc != 5) {
		fprintf(stderr, "USAGE: %s vid pid ifc ep\n", argv[0]);
		return 1;
	}

	vid = strtol(argv[1], NULL, 16);
	pid = strtol(argv[2], NULL, 16);
	ifc = strtol(argv[3], NULL, 16);
	ep = strtol(argv[4], NULL, 16);

	r = hammer(vid, pid, ifc, ep);
	printf("%d\n", r);
}

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Jeffrey Hein]

Hi Michal,

Both tests done. Intel xHCI 0000:00:14.0 (8086:a36d, Cannon Lake),
kernel 6.17.0-20-generic stock, stock uvcvideo. Two Razer Kiyo Pro
units (1532:0e05, fw 8.21) on root ports 2-1 and 2-2.

hammerint (2026-04-29): 60s per Kiyo. Kiyo 2-1 logged 413,738
submit/cancel cycles on EP 0x85 IN; Kiyo 2-2 logged 416,350. Both
timed out cleanly (rc 124 -- didn't kill the HC). Zero xhci_hc_died,
zero "event condition 198", no command timeouts in dmesg.

Caveat: usbcore.quirks=1532:0e05:k was on the cmdline that boot.
Hammerint runs the link at full throttle so it never gets idle enough
to attempt LPM transitions -- NO_LPM should be inert here -- but I can
re-run without quirks if you want a clean reading.

stream-mmap loop (2026-05-03): 300s per Kiyo, MJPG 1920x1080 @ 30fps,
no quirks on cmdline. Kiyo 2-1: 134 open-fmt-stream-close cycles on
/dev/video0. Kiyo 2-2: 92 on /dev/video2. Both clean, dmesg.post empty
of fatal patterns.

So Intel survives both reproducers in the windows tested. Doesn't
disprove your "looks like a HW bug" framing -- consistent with Intel's
xHCI ring tolerating the cancel/resubmit pattern that kills ASMedia.
The cascade path is silicon-dependent.

Note on scope: neither test exercises the rapid-SET_CUR pattern
(settings spam during a video call) that triggers the firmware lockup
in real-world use. That separate trigger does crash Intel --
stress-test-kiyo.sh hits hc_died around round ~25 on stock kernel --
and CTRL_THROTTLE in the patch series addresses it. So the patch
series argument doesn't change.

Side note: the same v4l2-ctl focus_absolute reproducer is reported on
Linux ARM (Pi), Windows, and macOS by another user (Razer Insider) --
supports the firmware-bug framing. Reffed in the v8 upstream report.

For v8: CTRL_THROTTLE addresses the trigger (rapid SET_CUR -> firmware
lockup), not the xHCI-side cascade. The xHCI side is your territory.

Forensics: https://github.com/jphein/kiyo-xhci-fix (raw run output
lives in gitignored results/ dirs locally; happy to send SUMMARY.log +
dmesg dumps off-list if useful).

JP

Jeffrey Pine Hein
Just plain helpful.
jphein.com ☀️ techempower.org
(530) 798-4099




On Sun, Apr 26, 2026 at 11:36 PM Michal Pecio <michal.pecio@gmail.com> wrote:
>
> On Mon, 13 Apr 2026 10:05:45 +0200, Michal Pecio wrote:
> > Question: can you kill it by starting some video application to set
> > the camera up, closing it and then running this loop?
> >
> > while :; do v4l2-ctl -d /dev/video0 --stream-mmap --stream-count=1; done
>
> Hi again,
>
> Any chance you could try it? And also the attached test program:
>
> cc -lusb-1.0 hammerint.c -o hammerint
> sudo ./hammerint 1532 0e05 0 85
>
> Initial arguments are VID:PID of the device, next is the number of
> an interface containing some interrupt endpoint and then the endpoint
> address (including 8_ if IN).
>
> I tried with a variety of SuperSpeed devices (UVC, NICs, hubs) and this
> reliably breaks ASMedia HCs within seconds. If the same is the case on
> Intel then it's a bigger problem than just UVC.
>
> The video streaming loop breaks even more controllers. I have some
> general idea how the streaming case could be dealt with, but not so
> much the interrupt one. Maybe rate limiting. I found that avoiding
> Set TR Dequeue to Link TRBs reduces failure rate, but not to zero.
>
> Long ago I also looked at the issued command sequences and I haven't
> noticed obvious errors or spec violations. Looks like a HW bug.
>
> Regards,
> Michal

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

On Fri, 10 Apr 2026 16:06:43 -0700, Jeffrey Hein wrote:
> Test 2: Michal's xhci patch ONLY (clean isolation)
> ====================================================
> Active: ONLY Michal's xhci patch. No usbcore.quirks cmdline, stock
> uvcvideo (DKMS module disabled), LPM and autosuspend at defaults.
> 
> Result: HC survived.
> 
> Video call ran successfully.

Something weird when video was being disabled:

[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x0000000272e42200, comp_code 13 after 13
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x0000000272e42230, comp_code 13 after 13
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Cancel URB 0000000052d839d8, dev 3.1, ep 0x81, starting at offset 0x272e42f00
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 36 ep 2
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x272e42f00 (dma) in stream 0 URB 0000000052d839d8
[...]
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: xhci_giveback_invalidated_tds: Giveback cancelled URB 0000000052d839d8 TD
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Cancel URB 00000000d8d84b58, dev 3.1, ep 0x81, starting at offset 0x260549210
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 36 ep 2 on endpoint
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 36 ep 2
[...]
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: drop ep 0x81, slot id 36, new drop flags = 0x8, new add flags = 0x0

Video started again, seemed to work for a while:

[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: add ep 0x81, slot id 36, new drop flags = 0x0, new add flags = 0x8
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: xhci_check_bandwidth called for udev 00000000e40f0c43
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: Successful Endpoint Configure command
[Fri Apr 10 15:44:47 2026] usb 2-3.1: Hub-initiated U1 disabled due to long timeout 16800us
[Fri Apr 10 15:44:47 2026] usb 2-3.1: Hub-initiated U1 disabled due to long timeout 132us
[Fri Apr 10 15:44:47 2026] usb 2-3.1: Hub-initiated U1 disabled due to long timeout 1050us
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: Set up evaluate context for LPM MEL change.
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: // Ding dong!
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: Successful evaluate context command
[Fri Apr 10 15:44:47 2026] usb 2-3.1: Disable U2, ESIT shorter than exit latency
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x0000000260549020, comp_code 13 after 13
[Fri Apr 10 15:44:47 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x0000000260549050, comp_code 13 after 13

Until it broke, not sure what caused this. No EP5IN unlinks here.

[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x0000000272e42690, comp_code 13 after 13
[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: Spurious event dma 0x0000000272e426d0, comp_code 13 after 13
[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: No Ping response error for slot 36 ep 2, Skip one Isoc TD
[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: No Ping response error for slot 36 ep 2, Skip one Isoc TD
[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: No Ping response error for slot 36 ep 2, Skip one Isoc TD

Then EP5IN also fails and is soft-retried, but it doesn't help.
Control requests get EPROTO or ETIMEDOUT as usual.

[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 36 ep 10 on endpoint
[Fri Apr 10 15:45:09 2026] xhci_hcd 0000:00:14.0: Soft-reset ep 10, slot 36

Looks like the device is dead indeed, or the HC broke down and
can't communiate with it.

Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

[Michal Pecio]

On Sat, 11 Apr 2026 00:48:05 +0300, Mathias Nyman wrote:
> > Five seconds later two control URBs are unlinked:
> > Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 00000000122aa5e2, dev 3.1, ep 0x0, starting at offset 0x11e227b40
> > Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: // Ding dong!
> > Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Cancel URB 000000008a55bcd3, dev 3.1, ep 0x0, starting at offset 0x11e227b20
> > Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Not queuing Stop Endpoint on slot 18 ep 0 in state 0x44  
> 
> log continues with:
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x11e227b40 (dma) in stream 0 URB 00000000122aa5e2
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Removing canceled TD starting at 0x11e227b20 (dma) in stream 0 URB 000000008a55bcd3
> Mar 30 16:59:21 katana kernel: xhci_hcd 0000:00:14.0: Set TR Deq ptr 0x11e227b40, cycle 0
> 
> One theory could be that xHC control endpoint refuses to restart when
> its dequeue pointer is moved to a no-op TD like in this case (second
> cancelled URB).

This could explain why it doesn't work later, but not why these URBs
have been unlinked after making no progress for 5 seconds. EP0 was
probably still functioning normally during those submit-unlink cycles
on 0x85 and there were no EP0 unlinks until these above.

Another corner case which could potentially confuse HCs is Set TR Deq
to a Link TRB, but it doesn't occur in this log on any endpoint.

By the way, are you able to find out what this is?
198 falls into the "vendor defined error" range and vendor is Intel.

crash-6.17.0-xhci-test-20260410-154243.log, isochronous URB unlink:
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Transfer error for slot 36 ep 2 on endpoint
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: ERROR Unknown event condition 198 for slot 36 ep 2 , HC probably busted
[Fri Apr 10 15:44:31 2026] xhci_hcd 0000:00:14.0: Stopped on Transfer TRB for slot 36 ep 2

[PATCH v5 3/3] media: uvcvideo: add quirks for Razer Kiyo Pro webcam

[JP Hein]

The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has
two failure modes that cascade into full xHCI host controller death,
disconnecting every USB device on the bus:

  1. LPM/autosuspend resume: the device fails to reinitialize its UVC
     endpoints on resume, producing EPIPE on SET_CUR. The stalled
     endpoint triggers an xHCI stop-endpoint timeout.

  2. Rapid control transfers: sustained rapid SET_CUR operations
     (hundreds over several seconds) overwhelm the firmware.

Add the device to the UVC driver table with:

  - UVC_QUIRK_CTRL_THROTTLE: rate-limit SET_CUR (50ms interval) and
    skip error-code queries after EPIPE to prevent crash trigger #2.

  - UVC_QUIRK_DISABLE_AUTOSUSPEND: prevent USB autosuspend transitions
    that trigger crash #1. Same approach as Insta360 Link.

  - UVC_QUIRK_NO_RESET_RESUME: avoid the fragile reset-during-resume
    path. Same approach as Logitech Rally Bar.

Cc: stable@vger.kernel.org
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2061177
Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_driver.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index b0ca81d92..e8b4de942 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2920,6 +2920,23 @@ static const struct usb_device_id uvc_ids[] = {
 	  .bInterfaceSubClass	= 1,
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+
+	/*
+	 * Razer Kiyo Pro -- firmware crashes under rapid control transfers
+	 * and on LPM/autosuspend resume, cascading into xHCI controller
+	 * death that disconnects all USB devices on the bus.
+	 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1532,
+	  .idProduct		= 0x0e05,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
+					| UVC_QUIRK_DISABLE_AUTOSUSPEND
+					| UVC_QUIRK_NO_RESET_RESUME) },
+
 	/* Kurokesu C1 PRO */
 	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
 				| USB_DEVICE_ID_MATCH_INT_INFO,
-- 
2.43.0

Re: [PATCH v5 3/3] media: uvcvideo: add quirks for Razer Kiyo Pro webcam

[Ricardo Ribalda]

Hi JP

When we add a quirk to the list we include the output of `lsusb -v -d
1532:` to the commit message. Please add it to your next version.

Thanks!

On Tue, 31 Mar 2026 at 02:38, JP Hein <jp@jphein.com> wrote:
>
> The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has
> two failure modes that cascade into full xHCI host controller death,
> disconnecting every USB device on the bus:
>
>   1. LPM/autosuspend resume: the device fails to reinitialize its UVC
>      endpoints on resume, producing EPIPE on SET_CUR. The stalled
>      endpoint triggers an xHCI stop-endpoint timeout.
>
>   2. Rapid control transfers: sustained rapid SET_CUR operations
>      (hundreds over several seconds) overwhelm the firmware.
>
> Add the device to the UVC driver table with:
>
>   - UVC_QUIRK_CTRL_THROTTLE: rate-limit SET_CUR (50ms interval) and
>     skip error-code queries after EPIPE to prevent crash trigger #2.
>
>   - UVC_QUIRK_DISABLE_AUTOSUSPEND: prevent USB autosuspend transitions
>     that trigger crash #1. Same approach as Insta360 Link.
>
>   - UVC_QUIRK_NO_RESET_RESUME: avoid the fragile reset-during-resume
>     path. Same approach as Logitech Rally Bar.
>
> Cc: stable@vger.kernel.org
> Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2061177
> Signed-off-by: JP Hein <jp@jphein.com>
> ---
>  drivers/media/usb/uvc/uvc_driver.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index b0ca81d92..e8b4de942 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -2920,6 +2920,23 @@ static const struct usb_device_id uvc_ids[] = {
>           .bInterfaceSubClass   = 1,
>           .bInterfaceProtocol   = 0,
>           .driver_info          = (kernel_ulong_t)&uvc_quirk_probe_minmax },
> +
> +       /*
> +        * Razer Kiyo Pro -- firmware crashes under rapid control transfers
> +        * and on LPM/autosuspend resume, cascading into xHCI controller
> +        * death that disconnects all USB devices on the bus.
> +        */
> +       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
> +                               | USB_DEVICE_ID_MATCH_INT_INFO,
> +         .idVendor             = 0x1532,
> +         .idProduct            = 0x0e05,
> +         .bInterfaceClass      = USB_CLASS_VIDEO,
> +         .bInterfaceSubClass   = 1,
> +         .bInterfaceProtocol   = 0,
> +         .driver_info          = UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
> +                                       | UVC_QUIRK_DISABLE_AUTOSUSPEND
> +                                       | UVC_QUIRK_NO_RESET_RESUME) },
> +
>         /* Kurokesu C1 PRO */
>         { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
>                                 | USB_DEVICE_ID_MATCH_INT_INFO,
> --
> 2.43.0
>


-- 
Ricardo Ribalda

Re: [PATCH v5 3/3] media: uvcvideo: add quirks for Razer Kiyo Pro webcam

[Jeffrey Hein]

Hi Ricardo,

On Thu, 9 Apr 2026 at 08:49, Ricardo Ribalda <ribalda@chromium.org> wrote:
> When we add a quirk to the list we include the output of `lsusb -v -d
> 1532:` to the commit message. Please add it to your next version.

Added the Device Descriptor section from lsusb -v to the v6 commit
message for patch 2/2.

Thanks,
JP

On Wed, Apr 8, 2026 at 11:50 PM Ricardo Ribalda <ribalda@chromium.org> wrote:
>
> Hi JP
>
> When we add a quirk to the list we include the output of `lsusb -v -d
> 1532:` to the commit message. Please add it to your next version.
>
> Thanks!
>
> On Tue, 31 Mar 2026 at 02:38, JP Hein <jp@jphein.com> wrote:
> >
> > The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has
> > two failure modes that cascade into full xHCI host controller death,
> > disconnecting every USB device on the bus:
> >
> >   1. LPM/autosuspend resume: the device fails to reinitialize its UVC
> >      endpoints on resume, producing EPIPE on SET_CUR. The stalled
> >      endpoint triggers an xHCI stop-endpoint timeout.
> >
> >   2. Rapid control transfers: sustained rapid SET_CUR operations
> >      (hundreds over several seconds) overwhelm the firmware.
> >
> > Add the device to the UVC driver table with:
> >
> >   - UVC_QUIRK_CTRL_THROTTLE: rate-limit SET_CUR (50ms interval) and
> >     skip error-code queries after EPIPE to prevent crash trigger #2.
> >
> >   - UVC_QUIRK_DISABLE_AUTOSUSPEND: prevent USB autosuspend transitions
> >     that trigger crash #1. Same approach as Insta360 Link.
> >
> >   - UVC_QUIRK_NO_RESET_RESUME: avoid the fragile reset-during-resume
> >     path. Same approach as Logitech Rally Bar.
> >
> > Cc: stable@vger.kernel.org
> > Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2061177
> > Signed-off-by: JP Hein <jp@jphein.com>
> > ---
> >  drivers/media/usb/uvc/uvc_driver.c | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> > index b0ca81d92..e8b4de942 100644
> > --- a/drivers/media/usb/uvc/uvc_driver.c
> > +++ b/drivers/media/usb/uvc/uvc_driver.c
> > @@ -2920,6 +2920,23 @@ static const struct usb_device_id uvc_ids[] = {
> >           .bInterfaceSubClass   = 1,
> >           .bInterfaceProtocol   = 0,
> >           .driver_info          = (kernel_ulong_t)&uvc_quirk_probe_minmax },
> > +
> > +       /*
> > +        * Razer Kiyo Pro -- firmware crashes under rapid control transfers
> > +        * and on LPM/autosuspend resume, cascading into xHCI controller
> > +        * death that disconnects all USB devices on the bus.
> > +        */
> > +       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
> > +                               | USB_DEVICE_ID_MATCH_INT_INFO,
> > +         .idVendor             = 0x1532,
> > +         .idProduct            = 0x0e05,
> > +         .bInterfaceClass      = USB_CLASS_VIDEO,
> > +         .bInterfaceSubClass   = 1,
> > +         .bInterfaceProtocol   = 0,
> > +         .driver_info          = UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
> > +                                       | UVC_QUIRK_DISABLE_AUTOSUSPEND
> > +                                       | UVC_QUIRK_NO_RESET_RESUME) },
> > +
> >         /* Kurokesu C1 PRO */
> >         { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
> >                                 | USB_DEVICE_ID_MATCH_INT_INFO,
> > --
> > 2.43.0
> >
>
>
> --
> Ricardo Ribalda



-- 
Jeffrey Pine Hein
Just plain helpful.
jphein.com ☀️ techempower.org
(530) 798-4099

[PATCH v6 0/2] media: uvcvideo: Add quirks to prevent Razer Kiyo Pro xHCI cascade failure

[JP Hein]

The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has a
well-documented failure mode that cascades into complete xHCI host
controller death, disconnecting every USB device on the bus -- including
keyboards and mice, requiring a hard reboot.

The device has two crash triggers:

  1. LPM/autosuspend resume: Device enters LPM or autosuspend, fails to
     reinitialize on resume, producing EPIPE (-32) on UVC SET_CUR. The
     stalled endpoint triggers an xHCI stop-endpoint timeout, and the
     kernel declares the host controller dead.

  2. Rapid control transfers: sustained rapid UVC control operations
     (hundreds over several seconds) overwhelm the firmware. The error-code
     query (GET_CUR on UVC_VC_REQUEST_ERROR_CODE_CONTROL) amplifies the
     failure by sending a second transfer to the already-stalling device,
     pushing it into a full lockup and xHCI controller death.

Patch 1 of the original 3-patch series (USB_QUIRK_NO_LPM for 1532:0e05)
has been merged by Greg Kroah-Hartman and backported to stable kernels
6.1, 6.6, 6.12, 6.18, and 6.19.

This v6 series covers the remaining two UVC patches:

Patch 1/2: UVC driver -- introduce UVC_QUIRK_CTRL_THROTTLE to rate-limit
  all USB control transfers (50ms minimum interval) in __uvc_query_ctrl()
  and skip the error-code query after EPIPE errors on affected devices.

Patch 2/2: UVC driver -- add Razer Kiyo Pro device table entry with
  UVC_QUIRK_CTRL_THROTTLE, UVC_QUIRK_DISABLE_AUTOSUSPEND, and
  UVC_QUIRK_NO_RESET_RESUME.

Changes since v5:
  - Moved throttle from uvc_query_ctrl() to __uvc_query_ctrl() so
    all callers are covered, including uvc_set_video_ctrl() which
    bypasses the higher-level function (Ricardo Ribalda)
  - Throttle now applies to all query types, not just SET_CUR -- the
    firmware doesn't distinguish between query directions under load
    (Ricardo Ribalda)
  - Added lsusb -v Device Descriptor to patch 2/2 commit message
    (Ricardo Ribalda)
  - Bug reproduced on two separate Kiyo Pro units, confirming not
    unit-specific

Changes since v4:
  - Dropped stable CC (new quirks, not regression fixes)
  - Updated cover letter with 6.17 test results

Changes since v3:
  - Regenerated patches against media-committers next branch to fix
    context mismatch (v3 was based on Ubuntu 6.8 source)

Tested on:
  - Kernel: 6.17.0-20-generic (Ubuntu 24.04 HWE) and 6.8.0-106-generic
  - Hardware: Intel Cannon Lake PCH xHCI (8086:a36d)
  - Device: Two Razer Kiyo Pro units (1532:0e05), firmware 1.5.0.1

Stress test, crash evidence, and debug logs:
  https://github.com/jphein/kiyo-xhci-fix

JP Hein (2):
  media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware
  media: uvcvideo: add Razer Kiyo Pro to device info table

 drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
 drivers/media/usb/uvc/uvc_video.c  | 30 ++++++++++++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h   |  3 +++
 3 files changed, 49 insertions(+)

-- 
2.43.0

[PATCH v6 1/2] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware

[JP Hein]

Some UVC devices have firmware that locks up under sustained rapid
USB control transfers, crashing the xHCI host controller and taking
all USB devices on the bus with it.

The Razer Kiyo Pro (1532:0e05) is the first known example: approximately
25 rapid consecutive control transfers cause the firmware to stall an
endpoint. The kernel's standard UVC error recovery (GET_CUR on
UVC_VC_REQUEST_ERROR_CODE_CONTROL) then sends a second transfer to the
already-stalling device, amplifying the failure into complete firmware
lockup and xHCI controller death.

Add UVC_QUIRK_CTRL_THROTTLE which:
  - Rate-limits all USB control transfers to 50ms intervals in
    __uvc_query_ctrl(), the lowest-level UVC control transfer function,
    ensuring all callers are throttled including uvc_set_video_ctrl()
    which bypasses uvc_query_ctrl()
  - Skips the error-code query after EPIPE to avoid amplifying stalls

The 50ms interval was determined experimentally: the device is stable
at this rate under sustained operation, while shorter intervals
eventually trigger the firmware bug.

Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_video.c | 30 ++++++++++++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h  |  3 +++
 2 files changed, 33 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index a5013a7..cee93ac 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -36,6 +36,26 @@ static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
 	unsigned int pipe;
 
+	/*
+	 * Rate-limit control transfers for devices with fragile firmware.
+	 * The Razer Kiyo Pro locks up under sustained rapid control
+	 * transfers (hundreds without delay), crashing the xHCI controller.
+	 * Throttle in this low-level function to cover all callers,
+	 * including uvc_set_video_ctrl() which bypasses uvc_query_ctrl().
+	 */
+	if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE) {
+		unsigned long min_interval = msecs_to_jiffies(50);
+
+		if (dev->last_ctrl_jiffies &&
+		    time_before(jiffies,
+				dev->last_ctrl_jiffies + min_interval)) {
+			unsigned long wait = dev->last_ctrl_jiffies +
+					     min_interval - jiffies;
+			msleep(jiffies_to_msecs(wait));
+		}
+		dev->last_ctrl_jiffies = jiffies;
+	}
+
 	pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
 			      : usb_sndctrlpipe(dev->udev, 0);
 	type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
@@ -108,6 +128,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 		return ret < 0 ? ret : -EPIPE;
 	}
 
+	/*
+	 * Skip the error code query for devices that crash under load.
+	 * The standard error-code query (GET_CUR on
+	 * UVC_VC_REQUEST_ERROR_CODE_CONTROL) sends a second USB transfer to
+	 * a device that is already stalling, which can amplify the failure
+	 * into a full firmware lockup and xHCI controller death.
+	 */
+	if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)
+		return -EPIPE;
+
 	/* Reuse data[0] to request the error code. */
 	tmp = *(u8 *)data;
 
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 757254f..31f2af5 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -78,6 +78,7 @@
 #define UVC_QUIRK_INVALID_DEVICE_SOF	0x00010000
 #define UVC_QUIRK_MJPEG_NO_EOF		0x00020000
 #define UVC_QUIRK_MSXU_META		0x00040000
+#define UVC_QUIRK_CTRL_THROTTLE		0x00080000
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED		0x00000001
@@ -583,6 +584,8 @@ struct uvc_device {
 	struct usb_interface *intf;
 	unsigned long warnings;
 	u32 quirks;
+	/* UVC control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
+	unsigned long last_ctrl_jiffies;
 	int intfnum;
 	char name[32];
 
-- 
2.43.0

Re: [PATCH v6 1/2] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware

[Ricardo Ribalda]

On Thu, 9 Apr 2026 at 09:44, JP Hein <jp@jphein.com> wrote:
>
> Some UVC devices have firmware that locks up under sustained rapid
> USB control transfers, crashing the xHCI host controller and taking
> all USB devices on the bus with it.
>
> The Razer Kiyo Pro (1532:0e05) is the first known example: approximately
> 25 rapid consecutive control transfers cause the firmware to stall an
> endpoint. The kernel's standard UVC error recovery (GET_CUR on
> UVC_VC_REQUEST_ERROR_CODE_CONTROL) then sends a second transfer to the
> already-stalling device, amplifying the failure into complete firmware
> lockup and xHCI controller death.
>
> Add UVC_QUIRK_CTRL_THROTTLE which:
>   - Rate-limits all USB control transfers to 50ms intervals in
>     __uvc_query_ctrl(), the lowest-level UVC control transfer function,
>     ensuring all callers are throttled including uvc_set_video_ctrl()
>     which bypasses uvc_query_ctrl()
>   - Skips the error-code query after EPIPE to avoid amplifying stalls
>
> The 50ms interval was determined experimentally: the device is stable
> at this rate under sustained operation, while shorter intervals
> eventually trigger the firmware bug.
>
> Signed-off-by: JP Hein <jp@jphein.com>
> ---
>  drivers/media/usb/uvc/uvc_video.c | 30 ++++++++++++++++++++++++++++++
>  drivers/media/usb/uvc/uvcvideo.h  |  3 +++
>  2 files changed, 33 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index a5013a7..cee93ac 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -36,6 +36,26 @@ static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>         u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
>         unsigned int pipe;
>
> +       /*
> +        * Rate-limit control transfers for devices with fragile firmware.
> +        * The Razer Kiyo Pro locks up under sustained rapid control
> +        * transfers (hundreds without delay), crashing the xHCI controller.
> +        * Throttle in this low-level function to cover all callers,
> +        * including uvc_set_video_ctrl() which bypasses uvc_query_ctrl().
> +        */
> +       if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE) {
> +               unsigned long min_interval = msecs_to_jiffies(50);
> +
> +               if (dev->last_ctrl_jiffies &&
> +                   time_before(jiffies,
> +                               dev->last_ctrl_jiffies + min_interval)) {
> +                       unsigned long wait = dev->last_ctrl_jiffies +
> +                                            min_interval - jiffies;
> +                       msleep(jiffies_to_msecs(wait));
> +               }
> +               dev->last_ctrl_jiffies = jiffies;
> +       }
> +
>         pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
>                               : usb_sndctrlpipe(dev->udev, 0);
>         type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
> @@ -108,6 +128,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>                 return ret < 0 ? ret : -EPIPE;
>         }
>
> +       /*
> +        * Skip the error code query for devices that crash under load.
> +        * The standard error-code query (GET_CUR on
> +        * UVC_VC_REQUEST_ERROR_CODE_CONTROL) sends a second USB transfer to
> +        * a device that is already stalling, which can amplify the failure
> +        * into a full firmware lockup and xHCI controller death.
> +        */
> +       if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)
> +               return -EPIPE;

I do not believe this is needed anymore now that the check is in the
inner funcion

> +
>         /* Reuse data[0] to request the error code. */
>         tmp = *(u8 *)data;
>
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 757254f..31f2af5 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -78,6 +78,7 @@
>  #define UVC_QUIRK_INVALID_DEVICE_SOF   0x00010000
>  #define UVC_QUIRK_MJPEG_NO_EOF         0x00020000
>  #define UVC_QUIRK_MSXU_META            0x00040000
> +#define UVC_QUIRK_CTRL_THROTTLE                0x00080000
>
>  /* Format flags */
>  #define UVC_FMT_FLAG_COMPRESSED                0x00000001
> @@ -583,6 +584,8 @@ struct uvc_device {
>         struct usb_interface *intf;
>         unsigned long warnings;
>         u32 quirks;
> +       /* UVC control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
> +       unsigned long last_ctrl_jiffies;
>         int intfnum;
>         char name[32];
>
> --
> 2.43.0
>


-- 
Ricardo Ribalda

Re: [PATCH v6 1/2] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware

[Jeffrey Hein]

Hi Ricardo,

Agreed -- the error-code query goes through __uvc_query_ctrl() now,
so it gets the 50ms throttle automatically. Dropped in v7.

Thanks,
JP



On Thu, Apr 9, 2026 at 12:57 AM Ricardo Ribalda <ribalda@chromium.org> wrote:
>
> On Thu, 9 Apr 2026 at 09:44, JP Hein <jp@jphein.com> wrote:
> >
> > Some UVC devices have firmware that locks up under sustained rapid
> > USB control transfers, crashing the xHCI host controller and taking
> > all USB devices on the bus with it.
> >
> > The Razer Kiyo Pro (1532:0e05) is the first known example: approximately
> > 25 rapid consecutive control transfers cause the firmware to stall an
> > endpoint. The kernel's standard UVC error recovery (GET_CUR on
> > UVC_VC_REQUEST_ERROR_CODE_CONTROL) then sends a second transfer to the
> > already-stalling device, amplifying the failure into complete firmware
> > lockup and xHCI controller death.
> >
> > Add UVC_QUIRK_CTRL_THROTTLE which:
> >   - Rate-limits all USB control transfers to 50ms intervals in
> >     __uvc_query_ctrl(), the lowest-level UVC control transfer function,
> >     ensuring all callers are throttled including uvc_set_video_ctrl()
> >     which bypasses uvc_query_ctrl()
> >   - Skips the error-code query after EPIPE to avoid amplifying stalls
> >
> > The 50ms interval was determined experimentally: the device is stable
> > at this rate under sustained operation, while shorter intervals
> > eventually trigger the firmware bug.
> >
> > Signed-off-by: JP Hein <jp@jphein.com>
> > ---
> >  drivers/media/usb/uvc/uvc_video.c | 30 ++++++++++++++++++++++++++++++
> >  drivers/media/usb/uvc/uvcvideo.h  |  3 +++
> >  2 files changed, 33 insertions(+)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> > index a5013a7..cee93ac 100644
> > --- a/drivers/media/usb/uvc/uvc_video.c
> > +++ b/drivers/media/usb/uvc/uvc_video.c
> > @@ -36,6 +36,26 @@ static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
> >         u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
> >         unsigned int pipe;
> >
> > +       /*
> > +        * Rate-limit control transfers for devices with fragile firmware.
> > +        * The Razer Kiyo Pro locks up under sustained rapid control
> > +        * transfers (hundreds without delay), crashing the xHCI controller.
> > +        * Throttle in this low-level function to cover all callers,
> > +        * including uvc_set_video_ctrl() which bypasses uvc_query_ctrl().
> > +        */
> > +       if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE) {
> > +               unsigned long min_interval = msecs_to_jiffies(50);
> > +
> > +               if (dev->last_ctrl_jiffies &&
> > +                   time_before(jiffies,
> > +                               dev->last_ctrl_jiffies + min_interval)) {
> > +                       unsigned long wait = dev->last_ctrl_jiffies +
> > +                                            min_interval - jiffies;
> > +                       msleep(jiffies_to_msecs(wait));
> > +               }
> > +               dev->last_ctrl_jiffies = jiffies;
> > +       }
> > +
> >         pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
> >                               : usb_sndctrlpipe(dev->udev, 0);
> >         type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
> > @@ -108,6 +128,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
> >                 return ret < 0 ? ret : -EPIPE;
> >         }
> >
> > +       /*
> > +        * Skip the error code query for devices that crash under load.
> > +        * The standard error-code query (GET_CUR on
> > +        * UVC_VC_REQUEST_ERROR_CODE_CONTROL) sends a second USB transfer to
> > +        * a device that is already stalling, which can amplify the failure
> > +        * into a full firmware lockup and xHCI controller death.
> > +        */
> > +       if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE)
> > +               return -EPIPE;
>
> I do not believe this is needed anymore now that the check is in the
> inner funcion
>
> > +
> >         /* Reuse data[0] to request the error code. */
> >         tmp = *(u8 *)data;
> >
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index 757254f..31f2af5 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -78,6 +78,7 @@
> >  #define UVC_QUIRK_INVALID_DEVICE_SOF   0x00010000
> >  #define UVC_QUIRK_MJPEG_NO_EOF         0x00020000
> >  #define UVC_QUIRK_MSXU_META            0x00040000
> > +#define UVC_QUIRK_CTRL_THROTTLE                0x00080000
> >
> >  /* Format flags */
> >  #define UVC_FMT_FLAG_COMPRESSED                0x00000001
> > @@ -583,6 +584,8 @@ struct uvc_device {
> >         struct usb_interface *intf;
> >         unsigned long warnings;
> >         u32 quirks;
> > +       /* UVC control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
> > +       unsigned long last_ctrl_jiffies;
> >         int intfnum;
> >         char name[32];
> >
> > --
> > 2.43.0
> >
>
>
> --
> Ricardo Ribalda

[PATCH v6 2/2] media: uvcvideo: add Razer Kiyo Pro to device info table

[JP Hein]

Add a device entry for the Razer Kiyo Pro (1532:0e05) with quirks to
work around firmware bugs that crash the xHCI host controller:

  UVC_QUIRK_CTRL_THROTTLE   - rate-limit control transfers and skip
                               error-code queries after EPIPE
  UVC_QUIRK_DISABLE_AUTOSUSPEND - prevent runtime suspend
  UVC_QUIRK_NO_RESET_RESUME - skip post-reset reinitialization

The firmware (v1.5.0.1) has two failure modes: it stalls endpoints
under rapid control transfers (~25 without delay), and it fails to
reinitialize properly after USB power state transitions. Both can
cascade into xHCI controller death, disconnecting all USB devices on
the bus.

Bug reproduced on two separate Kiyo Pro units running simultaneously,
confirming the issue is not unit-specific.

lsusb -v:
  Bus 002 Device 002: ID 1532:0e05 Razer USA, Ltd Razer Kiyo Pro
  Device Descriptor:
    bLength                18
    bDescriptorType         1
    bcdUSB               3.20
    bDeviceClass          239 Miscellaneous Device
    bDeviceSubClass         2 [unknown]
    bDeviceProtocol         1 Interface Association
    bMaxPacketSize0         9
    idVendor           0x1532 Razer USA, Ltd
    idProduct          0x0e05 Razer Kiyo Pro
    bcdDevice            8.21
    iManufacturer           1 Razer Inc
    iProduct                2 Razer Kiyo Pro
    iSerial                 0

Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 775bede..9b6df8e 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2880,6 +2880,22 @@ static const struct usb_device_id uvc_ids[] = {
 	  .bInterfaceSubClass	= 1,
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+
+	/*
+	 * Razer Kiyo Pro -- firmware crashes under rapid control transfers
+	 * and on LPM/autosuspend resume, cascading into xHCI controller
+	 * death that disconnects all USB devices on the bus.
+	 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1532,
+	  .idProduct		= 0x0e05,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
+					| UVC_QUIRK_DISABLE_AUTOSUSPEND
+					| UVC_QUIRK_NO_RESET_RESUME) },
 	/* Kurokesu C1 PRO */
 	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
 				| USB_DEVICE_ID_MATCH_INT_INFO,
-- 
2.43.0

Re: [PATCH v6 2/2] media: uvcvideo: add Razer Kiyo Pro to device info table

[Ricardo Ribalda]

Hi

On Thu, 9 Apr 2026 at 09:44, JP Hein <jp@jphein.com> wrote:
>
> Add a device entry for the Razer Kiyo Pro (1532:0e05) with quirks to
> work around firmware bugs that crash the xHCI host controller:
>
>   UVC_QUIRK_CTRL_THROTTLE   - rate-limit control transfers and skip
>                                error-code queries after EPIPE
>   UVC_QUIRK_DISABLE_AUTOSUSPEND - prevent runtime suspend
>   UVC_QUIRK_NO_RESET_RESUME - skip post-reset reinitialization
>
> The firmware (v1.5.0.1) has two failure modes: it stalls endpoints
> under rapid control transfers (~25 without delay), and it fails to
> reinitialize properly after USB power state transitions. Both can
> cascade into xHCI controller death, disconnecting all USB devices on
> the bus.
>
> Bug reproduced on two separate Kiyo Pro units running simultaneously,
> confirming the issue is not unit-specific.
>
> lsusb -v:
>   Bus 002 Device 002: ID 1532:0e05 Razer USA, Ltd Razer Kiyo Pro
>   Device Descriptor:
>     bLength                18
>     bDescriptorType         1
>     bcdUSB               3.20
>     bDeviceClass          239 Miscellaneous Device
>     bDeviceSubClass         2 [unknown]
>     bDeviceProtocol         1 Interface Association
>     bMaxPacketSize0         9
>     idVendor           0x1532 Razer USA, Ltd
>     idProduct          0x0e05 Razer Kiyo Pro
>     bcdDevice            8.21
>     iManufacturer           1 Razer Inc
>     iProduct                2 Razer Kiyo Pro
>     iSerial                 0
>

Is this the whole output of lsusb?? Can you try with lsusb -vv?

> Signed-off-by: JP Hein <jp@jphein.com>
> ---
>  drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index 775bede..9b6df8e 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -2880,6 +2880,22 @@ static const struct usb_device_id uvc_ids[] = {
>           .bInterfaceSubClass   = 1,
>           .bInterfaceProtocol   = 0,
>           .driver_info          = (kernel_ulong_t)&uvc_quirk_probe_minmax },
> +
> +       /*
> +        * Razer Kiyo Pro -- firmware crashes under rapid control transfers
> +        * and on LPM/autosuspend resume, cascading into xHCI controller
> +        * death that disconnects all USB devices on the bus.
> +        */
> +       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
> +                               | USB_DEVICE_ID_MATCH_INT_INFO,
> +         .idVendor             = 0x1532,
> +         .idProduct            = 0x0e05,
> +         .bInterfaceClass      = USB_CLASS_VIDEO,
> +         .bInterfaceSubClass   = 1,
> +         .bInterfaceProtocol   = 0,
> +         .driver_info          = UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
> +                                       | UVC_QUIRK_DISABLE_AUTOSUSPEND
> +                                       | UVC_QUIRK_NO_RESET_RESUME) },
>         /* Kurokesu C1 PRO */
>         { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
>                                 | USB_DEVICE_ID_MATCH_INT_INFO,
> --
> 2.43.0
>


-- 
Ricardo Ribalda

Re: [PATCH v6 2/2] media: uvcvideo: add Razer Kiyo Pro to device info table

[Jeffrey Hein]

Hi Ricardo,

Full lsusb -vv output included in the v7 commit message.

Thanks,
JP



On Thu, Apr 9, 2026 at 12:58 AM Ricardo Ribalda <ribalda@chromium.org> wrote:
>
> Hi
>
> On Thu, 9 Apr 2026 at 09:44, JP Hein <jp@jphein.com> wrote:
> >
> > Add a device entry for the Razer Kiyo Pro (1532:0e05) with quirks to
> > work around firmware bugs that crash the xHCI host controller:
> >
> >   UVC_QUIRK_CTRL_THROTTLE   - rate-limit control transfers and skip
> >                                error-code queries after EPIPE
> >   UVC_QUIRK_DISABLE_AUTOSUSPEND - prevent runtime suspend
> >   UVC_QUIRK_NO_RESET_RESUME - skip post-reset reinitialization
> >
> > The firmware (v1.5.0.1) has two failure modes: it stalls endpoints
> > under rapid control transfers (~25 without delay), and it fails to
> > reinitialize properly after USB power state transitions. Both can
> > cascade into xHCI controller death, disconnecting all USB devices on
> > the bus.
> >
> > Bug reproduced on two separate Kiyo Pro units running simultaneously,
> > confirming the issue is not unit-specific.
> >
> > lsusb -v:
> >   Bus 002 Device 002: ID 1532:0e05 Razer USA, Ltd Razer Kiyo Pro
> >   Device Descriptor:
> >     bLength                18
> >     bDescriptorType         1
> >     bcdUSB               3.20
> >     bDeviceClass          239 Miscellaneous Device
> >     bDeviceSubClass         2 [unknown]
> >     bDeviceProtocol         1 Interface Association
> >     bMaxPacketSize0         9
> >     idVendor           0x1532 Razer USA, Ltd
> >     idProduct          0x0e05 Razer Kiyo Pro
> >     bcdDevice            8.21
> >     iManufacturer           1 Razer Inc
> >     iProduct                2 Razer Kiyo Pro
> >     iSerial                 0
> >
>
> Is this the whole output of lsusb?? Can you try with lsusb -vv?
>
> > Signed-off-by: JP Hein <jp@jphein.com>
> > ---
> >  drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> > index 775bede..9b6df8e 100644
> > --- a/drivers/media/usb/uvc/uvc_driver.c
> > +++ b/drivers/media/usb/uvc/uvc_driver.c
> > @@ -2880,6 +2880,22 @@ static const struct usb_device_id uvc_ids[] = {
> >           .bInterfaceSubClass   = 1,
> >           .bInterfaceProtocol   = 0,
> >           .driver_info          = (kernel_ulong_t)&uvc_quirk_probe_minmax },
> > +
> > +       /*
> > +        * Razer Kiyo Pro -- firmware crashes under rapid control transfers
> > +        * and on LPM/autosuspend resume, cascading into xHCI controller
> > +        * death that disconnects all USB devices on the bus.
> > +        */
> > +       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
> > +                               | USB_DEVICE_ID_MATCH_INT_INFO,
> > +         .idVendor             = 0x1532,
> > +         .idProduct            = 0x0e05,
> > +         .bInterfaceClass      = USB_CLASS_VIDEO,
> > +         .bInterfaceSubClass   = 1,
> > +         .bInterfaceProtocol   = 0,
> > +         .driver_info          = UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
> > +                                       | UVC_QUIRK_DISABLE_AUTOSUSPEND
> > +                                       | UVC_QUIRK_NO_RESET_RESUME) },
> >         /* Kurokesu C1 PRO */
> >         { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
> >                                 | USB_DEVICE_ID_MATCH_INT_INFO,
> > --
> > 2.43.0
> >
>
>
> --
> Ricardo Ribalda

[PATCH v7 0/2] media: uvcvideo: Add quirks to prevent Razer Kiyo Pro xHCI cascade failure

[JP Hein]

The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has a
well-documented failure mode that cascades into complete xHCI host
controller death, disconnecting every USB device on the bus -- including
keyboards and mice, requiring a hard reboot.

The device has two crash triggers:

  1. LPM/autosuspend resume: Device enters LPM or autosuspend, fails to
     reinitialize on resume, producing EPIPE (-32) on UVC SET_CUR. The
     stalled endpoint triggers an xHCI stop-endpoint timeout, and the
     kernel declares the host controller dead.

  2. Rapid control transfers: sustained rapid UVC control operations
     (hundreds over several seconds) overwhelm the firmware.

Patch 1 of the original 3-patch series (USB_QUIRK_NO_LPM for 1532:0e05)
has been merged by Greg Kroah-Hartman and backported to stable kernels
6.1, 6.6, 6.12, 6.18, and 6.19.

This v7 series covers the remaining two UVC patches:

Patch 1/2: UVC driver -- introduce UVC_QUIRK_CTRL_THROTTLE to rate-limit
  all USB control transfers (50ms minimum interval) in __uvc_query_ctrl().

Patch 2/2: UVC driver -- add Razer Kiyo Pro device table entry with
  UVC_QUIRK_CTRL_THROTTLE, UVC_QUIRK_DISABLE_AUTOSUSPEND, and
  UVC_QUIRK_NO_RESET_RESUME.

Changes since v6:
  - Dropped the error-code query skip after EPIPE -- no longer needed
    since the throttle in __uvc_query_ctrl() already rate-limits the
    error-code query path (Ricardo Ribalda)
  - Included full lsusb -vv output in patch 2/2 commit message
    (Ricardo Ribalda)

Changes since v5:
  - Moved throttle from uvc_query_ctrl() to __uvc_query_ctrl() so
    all callers are covered, including uvc_set_video_ctrl() which
    bypasses the higher-level function (Ricardo Ribalda)
  - Throttle now applies to all query types, not just SET_CUR
    (Ricardo Ribalda)

Changes since v4:
  - Dropped stable CC (new quirks, not regression fixes)
  - Updated cover letter with 6.17 test results

Changes since v3:
  - Regenerated patches against media-committers next branch to fix
    context mismatch (v3 was based on Ubuntu 6.8 source)

Tested on:
  - Kernel: 6.17.0-20-generic (Ubuntu 24.04 HWE) and 6.8.0-106-generic
  - Hardware: Intel Cannon Lake PCH xHCI (8086:a36d)
  - Device: Two Razer Kiyo Pro units (1532:0e05), firmware 1.5.0.1

Stress test, crash evidence, and debug logs:
  https://github.com/jphein/kiyo-xhci-fix

JP Hein (2):
  media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware
  media: uvcvideo: add Razer Kiyo Pro to device info table

 drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
 drivers/media/usb/uvc/uvc_video.c  | 20 ++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h   |  3 +++
 3 files changed, 39 insertions(+)

-- 
2.43.0

[PATCH v7 1/2] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware

[JP Hein]

Some UVC devices have firmware that locks up under sustained rapid
USB control transfers, crashing the xHCI host controller and taking
all USB devices on the bus with it.

The Razer Kiyo Pro (1532:0e05) is the first known example: approximately
25 rapid consecutive control transfers cause the firmware to stall an
endpoint.

Add UVC_QUIRK_CTRL_THROTTLE which rate-limits all USB control transfers
to 50ms intervals in __uvc_query_ctrl(), the lowest-level UVC control
transfer function, ensuring all callers are throttled including
uvc_set_video_ctrl() which bypasses uvc_query_ctrl().

The 50ms interval was determined experimentally: the device is stable
at this rate under sustained operation, while shorter intervals
eventually trigger the firmware bug.

Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_video.c | 20 ++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h  |  3 +++
 2 files changed, 23 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index a5013a7..1d1206f 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -36,6 +36,26 @@ static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
 	unsigned int pipe;
 
+	/*
+	 * Rate-limit control transfers for devices with fragile firmware.
+	 * The Razer Kiyo Pro locks up under sustained rapid control
+	 * transfers (hundreds without delay), crashing the xHCI controller.
+	 * Throttle in this low-level function to cover all callers,
+	 * including uvc_set_video_ctrl() which bypasses uvc_query_ctrl().
+	 */
+	if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE) {
+		unsigned long min_interval = msecs_to_jiffies(50);
+
+		if (dev->last_ctrl_jiffies &&
+		    time_before(jiffies,
+				dev->last_ctrl_jiffies + min_interval)) {
+			unsigned long wait = dev->last_ctrl_jiffies +
+					     min_interval - jiffies;
+			msleep(jiffies_to_msecs(wait));
+		}
+		dev->last_ctrl_jiffies = jiffies;
+	}
+
 	pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
 			      : usb_sndctrlpipe(dev->udev, 0);
 	type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 757254f..31f2af5 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -78,6 +78,7 @@
 #define UVC_QUIRK_INVALID_DEVICE_SOF	0x00010000
 #define UVC_QUIRK_MJPEG_NO_EOF		0x00020000
 #define UVC_QUIRK_MSXU_META		0x00040000
+#define UVC_QUIRK_CTRL_THROTTLE		0x00080000
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED		0x00000001
@@ -583,6 +584,8 @@ struct uvc_device {
 	struct usb_interface *intf;
 	unsigned long warnings;
 	u32 quirks;
+	/* UVC control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
+	unsigned long last_ctrl_jiffies;
 	int intfnum;
 	char name[32];
 
-- 
2.43.0

[PATCH v7 2/2] media: uvcvideo: add Razer Kiyo Pro to device info table

[JP Hein]

Add a device entry for the Razer Kiyo Pro (1532:0e05) with quirks to
work around firmware bugs that crash the xHCI host controller:

  UVC_QUIRK_CTRL_THROTTLE   - rate-limit control transfers to prevent
                               firmware lockup under sustained load
  UVC_QUIRK_DISABLE_AUTOSUSPEND - prevent runtime suspend
  UVC_QUIRK_NO_RESET_RESUME - skip post-reset reinitialization

The firmware (v1.5.0.1) has two failure modes: it stalls endpoints
under rapid control transfers (~25 without delay), and it fails to
reinitialize properly after USB power state transitions. Both can
cascade into xHCI controller death, disconnecting all USB devices on
the bus.

Bug reproduced on two separate Kiyo Pro units running simultaneously,
confirming the issue is not unit-specific.

lsusb -vv:

  Bus 002 Device 002: ID 1532:0e05 Razer USA, Ltd Razer Kiyo Pro
  Device Descriptor:
    bLength                18
    bDescriptorType         1
    bcdUSB               3.20
    bDeviceClass          239 Miscellaneous Device
    bDeviceSubClass         2 [unknown]
    bDeviceProtocol         1 Interface Association
    bMaxPacketSize0         9
    idVendor           0x1532 Razer USA, Ltd
    idProduct          0x0e05 Razer Kiyo Pro
    bcdDevice            8.21
    iManufacturer           1 Razer Inc
    iProduct                2 Razer Kiyo Pro
    iSerial                 0
    bNumConfigurations      1
    Configuration Descriptor:
      bLength                 9
      bDescriptorType         2
      wTotalLength       0x05b4
      bNumInterfaces          4
      bConfigurationValue     1
      iConfiguration          0
      bmAttributes         0x80
        (Bus Powered)
      MaxPower              896mA
      Interface Association:
        bLength                 8
        bDescriptorType        11
        bFirstInterface         0
        bInterfaceCount         2
        bFunctionClass         14 Video
        bFunctionSubClass       3 Video Interface Collection
        bFunctionProtocol       0
        iFunction               0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        0
        bAlternateSetting       0
        bNumEndpoints           1
        bInterfaceClass        14 Video
        bInterfaceSubClass      1 Video Control
        bInterfaceProtocol      0
        iInterface              0
        VideoControl Interface Descriptor:
          bLength                13
          bDescriptorType        36
          bDescriptorSubtype      1 (HEADER)
          bcdUVC               1.00
          wTotalLength       0x0069
          dwClockFrequency       30.000000MHz
          bInCollection           1
          baInterfaceNr( 0)       1
        VideoControl Interface Descriptor:
          bLength                 9
          bDescriptorType        36
          bDescriptorSubtype      3 (OUTPUT_TERMINAL)
          bTerminalID             4
          wTerminalType      0x0101 USB Streaming
          bAssocTerminal          0
          bSourceID               2
          iTerminal               0
        VideoControl Interface Descriptor:
          bLength                27
          bDescriptorType        36
          bDescriptorSubtype      6 (EXTENSION_UNIT)
          bUnitID                 2
          guidExtensionCode         {2c49d16a-32b8-4485-3ea8-643a152362f2}
          bNumControls            6
          bNrInPins               1
          baSourceID( 0)          6
          bControlSize            2
          bmControls( 0)       0x3f
          bmControls( 1)       0x00
          iExtension              0
        VideoControl Interface Descriptor:
          bLength                27
          bDescriptorType        36
          bDescriptorSubtype      6 (EXTENSION_UNIT)
          bUnitID                 6
          guidExtensionCode         {23e49ed0-1178-4f31-ae52-d2fb8a8d3b48}
          bNumControls            5
          bNrInPins               1
          baSourceID( 0)          3
          bControlSize            2
          bmControls( 0)       0xff
          bmControls( 1)       0x7f
          iExtension              0
        VideoControl Interface Descriptor:
          bLength                18
          bDescriptorType        36
          bDescriptorSubtype      2 (INPUT_TERMINAL)
          bTerminalID             1
          wTerminalType      0x0201 Camera Sensor
          bAssocTerminal          0
          iTerminal               0
          wObjectiveFocalLengthMin      0
          wObjectiveFocalLengthMax      0
          wOcularFocalLength            0
          bControlSize                  3
          bmControls           0x00020a2e
            Auto-Exposure Mode
            Auto-Exposure Priority
            Exposure Time (Absolute)
            Focus (Absolute)
            Zoom (Absolute)
            PanTilt (Absolute)
            Focus, Auto
        VideoControl Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      5 (PROCESSING_UNIT)
        Warning: Descriptor too short
          bUnitID                 3
          bSourceID               1
          wMaxMultiplier          0
          bControlSize            2
          bmControls     0x0000175b
            Brightness
            Contrast
            Saturation
            Sharpness
            White Balance Temperature
            Backlight Compensation
            Gain
            Power Line Frequency
            White Balance Temperature, Auto
          iProcessing             0
          bmVideoStandards     0xff
            None
            NTSC - 525/60
            PAL - 625/50
            SECAM - 625/50
            NTSC - 625/50
            PAL - 525/60
        Endpoint Descriptor:
          bLength                 7
          bDescriptorType         5
          bEndpointAddress     0x85  EP 5 IN
          bmAttributes            3
            Transfer Type            Interrupt
            Synch Type               None
            Usage Type               Data
          wMaxPacketSize     0x0040  1x 64 bytes
          bInterval               8
          bMaxBurst               0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        1
        bAlternateSetting       0
        bNumEndpoints           0
        bInterfaceClass        14 Video
        bInterfaceSubClass      2 Video Streaming
        bInterfaceProtocol      0
        iInterface              0
        VideoStreaming Interface Descriptor:
          bLength                            17
          bDescriptorType                    36
          bDescriptorSubtype                  1 (INPUT_HEADER)
          bNumFormats                         4
          wTotalLength                   0x03e6
          bEndpointAddress                 0x81  EP 1 IN
          bmInfo                              0
          bTerminalLink                       4
          bStillCaptureMethod                 0
          bTriggerSupport                     0
          bTriggerUsage                       0
          bControlSize                        1
          bmaControls( 0)                     0
          bmaControls( 1)                     0
          bmaControls( 2)                     0
          bmaControls( 3)                     0
        VideoStreaming Interface Descriptor:
          bLength                            27
          bDescriptorType                    36
          bDescriptorSubtype                  4 (FORMAT_UNCOMPRESSED)
          bFormatIndex                        1
          bNumFrameDescriptors                4
          guidFormat                            {32595559-0000-0010-8000-00aa00389b71}
          bBitsPerPixel                      16
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 2 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                294912000
          dwMaxBitRate                294912000
          dwMaxVideoFrameBufferSize      614400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         7
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                221184000
          dwMaxBitRate                221184000
          dwMaxVideoFrameBufferSize      460800
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                        11
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                884736000
          dwMaxBitRate                884736000
          dwMaxVideoFrameBufferSize     1843200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                        13
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                1990656000
          dwMaxBitRate                1990656000
          dwMaxVideoFrameBufferSize     4147200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
        VideoStreaming Interface Descriptor:
          bLength                            11
          bDescriptorType                    36
          bDescriptorSubtype                  6 (FORMAT_MJPEG)
          bFormatIndex                        2
          bNumFrameDescriptors                4
          bFlags                              0
            Fixed-size samples: No
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 1 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                294912000
          dwMaxBitRate                294912000
          dwMaxVideoFrameBufferSize      614400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                         7
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                221184000
          dwMaxBitRate                221184000
          dwMaxVideoFrameBufferSize      460800
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                        11
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                884736000
          dwMaxBitRate                884736000
          dwMaxVideoFrameBufferSize     1843200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                        13
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                1990656000
          dwMaxBitRate                1990656000
          dwMaxVideoFrameBufferSize     4147200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
        VideoStreaming Interface Descriptor:
          bLength                            28
          bDescriptorType                    36
          bDescriptorSubtype                 16 (FORMAT_FRAME_BASED)
          bFormatIndex                        3
          bNumFrameDescriptors                4
          guidFormat                            {34363248-0000-0010-8000-00aa00389b71}
          bBitsPerPixel                      16
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 2 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
          bVariableSize                     1
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                         9
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                        15
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                        17
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
        VideoStreaming Interface Descriptor:
          bLength                            27
          bDescriptorType                    36
          bDescriptorSubtype                  4 (FORMAT_UNCOMPRESSED)
          bFormatIndex                        4
          bNumFrameDescriptors                4
          guidFormat                            {3231564e-0000-0010-8000-00aa00389b71}
          bBitsPerPixel                      12
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 2 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                221184000
          dwMaxBitRate                221184000
          dwMaxVideoFrameBufferSize      460800
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         2
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                165888000
          dwMaxBitRate                165888000
          dwMaxVideoFrameBufferSize      345600
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         3
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                663552000
          dwMaxBitRate                663552000
          dwMaxVideoFrameBufferSize     1382400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         4
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                1492992000
          dwMaxBitRate                1492992000
          dwMaxVideoFrameBufferSize     3110400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        1
        bAlternateSetting       1
        bNumEndpoints           1
        bInterfaceClass        14 Video
        bInterfaceSubClass      2 Video Streaming
        bInterfaceProtocol      0
        iInterface              0
        Endpoint Descriptor:
          bLength                 7
          bDescriptorType         5
          bEndpointAddress     0x81  EP 1 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0400  1x 1024 bytes
          bInterval               1
          bMaxBurst               0
          Mult                    2
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        1
        bAlternateSetting       2
        bNumEndpoints           1
        bInterfaceClass        14 Video
        bInterfaceSubClass      2 Video Streaming
        bInterfaceProtocol      0
        iInterface              0
        Endpoint Descriptor:
          bLength                 7
          bDescriptorType         5
          bEndpointAddress     0x81  EP 1 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0400  1x 1024 bytes
          bInterval               1
          bMaxBurst              10
          Mult                    2
      Interface Association:
        bLength                 8
        bDescriptorType        11
        bFirstInterface         2
        bInterfaceCount         2
        bFunctionClass          1 Audio
        bFunctionSubClass       2 Streaming
        bFunctionProtocol       0
        iFunction               0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        2
        bAlternateSetting       0
        bNumEndpoints           0
        bInterfaceClass         1 Audio
        bInterfaceSubClass      1 Control Device
        bInterfaceProtocol      0
        iInterface              0
        AudioControl Interface Descriptor:
          bLength                 9
          bDescriptorType        36
          bDescriptorSubtype      1 (HEADER)
          bcdADC               1.00
          wTotalLength       0x0026
          bInCollection           1
          baInterfaceNr(0)        3
        AudioControl Interface Descriptor:
          bLength                12
          bDescriptorType        36
          bDescriptorSubtype      2 (INPUT_TERMINAL)
          bTerminalID             1
          wTerminalType      0x0201 Microphone
          bAssocTerminal          0
          bNrChannels             2
          wChannelConfig     0x0003
            Left Front (L)
            Right Front (R)
          iChannelNames           0
          iTerminal               0
        AudioControl Interface Descriptor:
          bLength                 9
          bDescriptorType        36
          bDescriptorSubtype      3 (OUTPUT_TERMINAL)
          bTerminalID             3
          wTerminalType      0x0101 USB Streaming
          bAssocTerminal          0
          bSourceID               5
          iTerminal               0
        AudioControl Interface Descriptor:
          bLength                 8
          bDescriptorType        36
          bDescriptorSubtype      6 (FEATURE_UNIT)
          bUnitID                 5
          bSourceID               1
          bControlSize            1
          bmaControls(0)       0x03
            Mute Control
            Volume Control
          iFeature                0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       0
        bNumEndpoints           0
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       1
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        48000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x00c4  1x 196 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       2
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        16000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0044  1x 68 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       3
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        24000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0064  1x 100 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       4
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        32000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0084  1x 132 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
  Binary Object Store Descriptor:
    bLength                 5
    bDescriptorType        15
    wTotalLength       0x0016
    bNumDeviceCaps          2
    USB 2.0 Extension Device Capability:
      bLength                 7
      bDescriptorType        16
      bDevCapabilityType      2
      bmAttributes   0x00000006
        BESL Link Power Management (LPM) Supported
    SuperSpeed USB Device Capability:
      bLength                10
      bDescriptorType        16
      bDevCapabilityType      3
      bmAttributes         0x00
      wSpeedsSupported   0x000e
        Device can operate at Full Speed (12Mbps)
        Device can operate at High Speed (480Mbps)
        Device can operate at SuperSpeed (5Gbps)
      bFunctionalitySupport   2
        Lowest fully-functional device speed is High Speed (480Mbps)
      bU1DevExitLat          10 micro seconds
      bU2DevExitLat         256 micro seconds
  Device Status:     0x0000
    (Bus Powered)

Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 775bede..9b6df8e 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2880,6 +2880,22 @@ static const struct usb_device_id uvc_ids[] = {
 	  .bInterfaceSubClass	= 1,
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+
+	/*
+	 * Razer Kiyo Pro -- firmware crashes under rapid control transfers
+	 * and on LPM/autosuspend resume, cascading into xHCI controller
+	 * death that disconnects all USB devices on the bus.
+	 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1532,
+	  .idProduct		= 0x0e05,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
+					| UVC_QUIRK_DISABLE_AUTOSUSPEND
+					| UVC_QUIRK_NO_RESET_RESUME) },
 	/* Kurokesu C1 PRO */
 	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
 				| USB_DEVICE_ID_MATCH_INT_INFO,
-- 
2.43.0

Re: [PATCH v7 0/2] media: uvcvideo: Add quirks to prevent Razer Kiyo Pro xHCI cascade failure

[Michal Pecio]

On Thu,  9 Apr 2026 17:28:29 -0700, JP Hein wrote:
> The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has
> a well-documented failure mode that cascades into complete xHCI host
> controller death, disconnecting every USB device on the bus --
> including keyboards and mice, requiring a hard reboot.

For the record, reloading xhci-pci is usually enough to fix this.

> The device has two crash triggers:
> 
>   1. LPM/autosuspend resume: Device enters LPM or autosuspend, fails
>      to reinitialize on resume, producing EPIPE (-32) on UVC SET_CUR.
>      The stalled endpoint triggers an xHCI stop-endpoint timeout, and
>      the kernel declares the host controller dead.
> 
>   2. Rapid control transfers: sustained rapid UVC control operations
>      (hundreds over several seconds) overwhelm the firmware.

That's a bit speculative, it's not entirely clear what happens here.
2 seems possible, but Stop Endpoint timeout and some weird error codes
seen in those logs looks like problems with the HC.

And I known that some HCs are reliably killed by stopping SuperSpeed
UVC streams, at least with my camera.

> Patch 1 of the original 3-patch series (USB_QUIRK_NO_LPM for
> 1532:0e05) has been merged by Greg Kroah-Hartman and backported to
> stable kernels 6.1, 6.6, 6.12, 6.18, and 6.19.
> 
> This v7 series covers the remaining two UVC patches:
> 
> Patch 1/2: UVC driver -- introduce UVC_QUIRK_CTRL_THROTTLE to
> rate-limit all USB control transfers (50ms minimum interval) in
> __uvc_query_ctrl().
> 
> Patch 2/2: UVC driver -- add Razer Kiyo Pro device table entry with
>   UVC_QUIRK_CTRL_THROTTLE, UVC_QUIRK_DISABLE_AUTOSUSPEND, and
>   UVC_QUIRK_NO_RESET_RESUME.

Do these patches actually make a practical difference?

If I'm not mistaken, the results of testing on 6.17 are:

1. The original trigger (spamming UVC control requests alone) doesn't
   cause breakage anymore.

2. New problems are seen when doing the above while streaming video,
   and they are still seen even with the UVC patches applied.

Re: [PATCH v7 0/2] media: uvcvideo: Add quirks to prevent Razer Kiyo Pro xHCI cascade failure

[Jeffrey Hein]

On Mon, 13 Apr 2026 22:40:38 +0200, Michal Pecio wrote:
> For the record, reloading xhci-pci is usually enough to fix this.

You're right that reloading xhci-pci is a recovery path -- I'll note
it. The reason the cover letter says "hard reboot" is that when the HC
dies, every USB device on the bus disconnects with it, keyboard and
mouse included, so triggering the reload requires SSH from a second
machine, SysRq, or some other non-USB input path. For most users on a
single-machine desktop the practical recovery is a reboot. I'll reword
in the next respin to capture both: "recovery requires rmmod/modprobe
xhci-pci or a reboot; since the local input devices disconnect with
the HC, most single-machine users will reboot."

> That's a bit speculative, it's not entirely clear what happens here.
> 2 seems possible, but Stop Endpoint timeout and some weird error codes
> seen in those logs looks like problems with the HC.

Fair. I'll reword trigger #2 to drop the firmware-internals claim and
describe only what we can observe: sustained rapid control activity
correlates with the device entering a stalled state that then triggers
a separate xHCI-layer failure. Your dual-cancel discussion with Mathias
and the vendor-defined event 198 are the right place to characterise
the HC-side mechanism; these UVC patches don't claim to explain or fix
it.

> Do these patches actually make a practical difference?

For CTRL_THROTTLE vs no mitigation, yes -- and I should have led with
this. Without any patches the stress test crashes the HC reproducibly
at round ~25 (many dmesg captures on file). With CTRL_THROTTLE alone
the same stress test runs 500+ rounds without failure. I also tested
USB_QUIRK_NO_LPM, DISABLE_AUTOSUSPEND, and avoid_reset_quirk
individually via sysfs, and each failed to prevent the stress-test
crash in isolation; a combined udev rule with all three still crashed
at ~round 25. Only CTRL_THROTTLE (or the coarser
USB_QUIRK_DELAY_CTRL_MSG at 200 ms) prevented it.

Where my data is actually thin is the interaction with your xhci test
patch specifically. The Apr 10 runs comparing "full stack + your
patch" (HC died) against "your patch alone" (HC survived) are N=1
each, and the lock-up path is timing-sensitive, so I shouldn't be
drawing conclusions from single outcomes on that axis. Before
respinning, I'll run a replication matrix on 6.17:

  * stock (no patches)
  * stock + your xhci test patch
  * stock + NO_LPM
  * stock + NO_LPM + CTRL_THROTTLE
  * stock + NO_LPM + CTRL_THROTTLE + your xhci test patch

each under two workloads -- control-spam only, and control-spam during
an active v4l2 stream -- at N >= 5 per cell, with xhci_hcd and usbcore
dynamic debug enabled. I'll post the matrix with logs before the next
respin. That should tell us whether CTRL_THROTTLE still earns its keep
once your xhci patch is applied, which is the real open question.

Two things I'll fold in regardless of how the matrix reads:

  1. The cover-letter language fixes above.

  2. Clarifying in the commit messages that CTRL_THROTTLE and the
     device-table entry are a device-local firmware-workaround layer,
     not a claim on the HC-side issue -- which is Mathias's territory
     and I don't want to conflate them.

If the matrix shows the throttle doesn't buy anything above your xhci
patch, I'll say so plainly and we can discuss whether the device-table
entry alone (DISABLE_AUTOSUSPEND + NO_RESET_RESUME, matching the
Logitech Rally Bar entry in uvc_driver.c) is still worth landing on
its own.

Thanks for the pushback -- it forced me to look harder at my own data.

JP


On Mon, Apr 13, 2026 at 1:40 PM Michal Pecio <michal.pecio@gmail.com> wrote:
>
> On Thu,  9 Apr 2026 17:28:29 -0700, JP Hein wrote:
> > The Razer Kiyo Pro (1532:0e05) is a USB 3.0 webcam whose firmware has
> > a well-documented failure mode that cascades into complete xHCI host
> > controller death, disconnecting every USB device on the bus --
> > including keyboards and mice, requiring a hard reboot.
>
> For the record, reloading xhci-pci is usually enough to fix this.
>
> > The device has two crash triggers:
> >
> >   1. LPM/autosuspend resume: Device enters LPM or autosuspend, fails
> >      to reinitialize on resume, producing EPIPE (-32) on UVC SET_CUR.
> >      The stalled endpoint triggers an xHCI stop-endpoint timeout, and
> >      the kernel declares the host controller dead.
> >
> >   2. Rapid control transfers: sustained rapid UVC control operations
> >      (hundreds over several seconds) overwhelm the firmware.
>
> That's a bit speculative, it's not entirely clear what happens here.
> 2 seems possible, but Stop Endpoint timeout and some weird error codes
> seen in those logs looks like problems with the HC.
>
> And I known that some HCs are reliably killed by stopping SuperSpeed
> UVC streams, at least with my camera.
>
> > Patch 1 of the original 3-patch series (USB_QUIRK_NO_LPM for
> > 1532:0e05) has been merged by Greg Kroah-Hartman and backported to
> > stable kernels 6.1, 6.6, 6.12, 6.18, and 6.19.
> >
> > This v7 series covers the remaining two UVC patches:
> >
> > Patch 1/2: UVC driver -- introduce UVC_QUIRK_CTRL_THROTTLE to
> > rate-limit all USB control transfers (50ms minimum interval) in
> > __uvc_query_ctrl().
> >
> > Patch 2/2: UVC driver -- add Razer Kiyo Pro device table entry with
> >   UVC_QUIRK_CTRL_THROTTLE, UVC_QUIRK_DISABLE_AUTOSUSPEND, and
> >   UVC_QUIRK_NO_RESET_RESUME.
>
> Do these patches actually make a practical difference?
>
> If I'm not mistaken, the results of testing on 6.17 are:
>
> 1. The original trigger (spamming UVC control requests alone) doesn't
>    cause breakage anymore.
>
> 2. New problems are seen when doing the above while streaming video,
>    and they are still seen even with the UVC patches applied.



-- 
Jeffrey Pine Hein
Just plain helpful.
jphein.com ☀️ techempower.org
(530) 798-4099

[PATCH v8 0/2] media: uvcvideo: Quirks for Razer Kiyo Pro firmware lockup

[JP Hein]

The Razer Kiyo Pro (1532:0e05) firmware has multiple lockup paths that
cascade into xHCI host controller death, disconnecting every USB device
on the bus -- including keyboard and mouse, requiring a hard reboot.

The bug has two layers:

* Trigger (device firmware -- Sigmastar SAV630D + AIT camera, fw 1.5.0.1
  / bcdDevice 8.21). Three failure paths:

  - LPM / autosuspend resume: device fails to reinitialize after a USB
    Link Power Management transition, returning EPIPE on the first
    UVC SET_CUR. Mitigated by USB_QUIRK_NO_LPM (patch 1 of the
    original 3-patch series, merged by Greg Kroah-Hartman, backported
    to stable 6.1, 6.6, 6.12, 6.18, and 6.19).
  - Rapid control transfers: sustained UVC control operations overwhelm
    the firmware, causing endpoint stalls. Mitigated by
    UVC_QUIRK_CTRL_THROTTLE (this series).
  - USB descriptor spec violation: SuperSpeed Endpoint Companion
    descriptor for EP5 IN (interrupt) declares wBytesPerInterval=8 but
    wMaxPacketSize=64. xHCI derives max_esit_payload from the former,
    underallocating bandwidth and producing spurious COMP_SHORT_PACKET
    events under load.

* Cascade (host controller). Firmware lockup or stalled endpoint
  cascades to xhci_hc_died(). Severity is silicon-dependent: per Michal
  Pecio's reports on linux-usb, ASMedia hosts hit hc_died in seconds
  under both the dual-cancel and SHORT_PACKET-flood paths. Intel Cannon
  Lake (this series tested) survives the cancel/resubmit and stream-mmap
  teardown reproducers clean.

This series addresses trigger #2 only. Trigger #1 is already mitigated
upstream. Trigger #3 is a host-side bandwidth-allocation concern;
Michal Pecio is prototyping an xhci ring patch (clamp max_esit_payload
+ retry on COMP_SHORT_PACKET) on linux-usb. The two efforts are
complementary: this series prevents the firmware from getting into the
locked state that triggers the cascade; Michal's patch makes the host
side more resilient when the firmware does lock up.

Why kernel-side mitigation is the only viable path: we attempted a
firmware fix. The wBytesPerInterval bug byte is at offset 0x1F570A in
the raw firmware image distributed with Razer's Windows updater. We
reverse-engineered the UVC Extension Unit flash protocol the updater
uses (XU6 selector 3, 32-byte chunks, status 0x82 = success) and
implemented a Linux flash tool. The device acknowledges writes and
reports burn-complete but does not persist after power cycle. The
ROM-boot recovery entry path is locked out in production firmware.
There is no userspace path to fix the bug on shipped devices.
Forensics: firmware-analysis/ in the linked repository.

This v8 series covers the remaining two UVC patches:

Patch 1/2: UVC driver -- introduce UVC_QUIRK_CTRL_THROTTLE to rate-limit
  all USB control transfers (50ms minimum interval) in
  __uvc_query_ctrl(). The 50ms threshold is the minimum that empirically
  prevents firmware overflow, 4x shorter than USB_QUIRK_DELAY_CTRL_MSG's
  200ms and scoped specifically to UVC. Quirk is opt-in by device-table
  entry; non-quirked devices are unaffected.

Patch 2/2: UVC driver -- add Razer Kiyo Pro device table entry with
  UVC_QUIRK_CTRL_THROTTLE, UVC_QUIRK_DISABLE_AUTOSUSPEND, and
  UVC_QUIRK_NO_RESET_RESUME. CTRL_THROTTLE rate-limits the rapid-SET_CUR
  trigger (verified via stress test, see results below). The other two
  cover related failure paths in line with patterns established for
  similar fragile UVC firmware (Insta360 Link, Logitech Rally Bar).

Test results:

* stress-test-kiyo.sh (rapid SET_CUR flood, ~25 controls per round):
  - stock kernel + stock uvcvideo, no quirks: hc_died at round ~25
  - with UVC_QUIRK_CTRL_THROTTLE active: 500+ rounds clean

* Michal Pecio's hammerint (libusb submit/cancel on EP 0x85 IN), Intel
  Cannon Lake, 60s x 2 Kiyos:
  - 413,738 and 416,350 cycles respectively, both timed out cleanly.
    No xhci_hc_died, no "event condition 198", no command timeouts.
    NO_LPM was active that boot but inert at this rate (~6900 cycles/sec
    leaves no idle time for LPM transitions).

* stream-mmap loop (v4l2-ctl open / format / stream / close), Intel
  Cannon Lake, 300s x 2 Kiyos at MJPG 1920x1080 @ 30fps, no quirks
  active:
  - 134 and 92 cycles respectively, both clean. No fatal patterns in
    dmesg.post.

Cross-platform corroboration: the same v4l2-ctl focus_absolute
reproducer is reported on Linux ARM (Raspberry Pi), Windows, and macOS
by independent users. Refs in kernel-patches/upstream-report.md
section "Third-Party Reproduction Evidence".

Changes since v7:
  - Reframed scope: this series mitigates the firmware-lockup trigger,
    not the xHCI cascade. The cascade is silicon-dependent and is
    being addressed separately by Michal Pecio's xhci ring patch on
    linux-usb.
  - Added test data: hammerint and stream-mmap loop on Intel Cannon
    Lake, both clean (~414K/416K cycles per Kiyo over 60s and
    134/92 cycles per Kiyo over 300s respectively).
  - Added firmware reverse-engineering note: bug byte located at
    0x1F570A in fwimage.bin, UVC XU flash protocol implemented, no
    userspace path to persist firmware fixes on shipped devices.
  - Cross-platform corroboration cited.
  - No code changes from v7. v8 is a re-send to integrate post-v7
    discussion on the v5 2/3 chain.

Changes since v6:
  - Dropped error-code query skip after EPIPE (Ricardo Ribalda)
  - Included full lsusb -vv in patch 2/2 commit message (Ricardo Ribalda)

Changes since v5:
  - Moved throttle from uvc_query_ctrl() to __uvc_query_ctrl() so all
    callers are covered (Ricardo Ribalda)
  - Throttle applies to all query types, not just SET_CUR (Ricardo
    Ribalda)

Tested on:
  - Kernel: 6.17.0-20-generic (Ubuntu 24.04 HWE), 6.17.0-xhci-test
    (with Michal Pecio's max_esit_payload + COMP_SHORT_PACKET retry),
    6.8.0-106-generic
  - Hardware: Intel Cannon Lake PCH xHCI (8086:a36d)
  - Device: Two Razer Kiyo Pro units (1532:0e05), firmware 1.5.0.1
    (bcdDevice 8.21)

Reproducers and full debug logs:
  https://github.com/jphein/kiyo-xhci-fix
  - kernel-patches/stress-test-kiyo.sh
  - kernel-patches/matrix/michal-tests/hammerint.c
    (Michal Pecio's, alongside the harness)
  - kernel-patches/matrix/michal-tests/stream-loop.sh

JP Hein (2):
  media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware
  media: uvcvideo: add Razer Kiyo Pro to device info table

 drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
 drivers/media/usb/uvc/uvc_video.c  | 20 ++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h   |  3 +++
 3 files changed, 39 insertions(+)

--
2.43.0

[PATCH v8 1/2] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile USB firmware

[JP Hein]

Some UVC devices have firmware that locks up under sustained rapid
USB control transfers, crashing the xHCI host controller and taking
all USB devices on the bus with it.

The Razer Kiyo Pro (1532:0e05) is the first known example: approximately
25 rapid consecutive control transfers cause the firmware to stall an
endpoint.

Add UVC_QUIRK_CTRL_THROTTLE which rate-limits all USB control transfers
to 50ms intervals in __uvc_query_ctrl(), the lowest-level UVC control
transfer function, ensuring all callers are throttled including
uvc_set_video_ctrl() which bypasses uvc_query_ctrl().

The 50ms interval was determined experimentally: the device is stable
at this rate under sustained operation, while shorter intervals
eventually trigger the firmware bug.

Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_video.c | 20 ++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h  |  3 +++
 2 files changed, 23 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index a5013a7..1d1206f 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -36,6 +36,26 @@ static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 	u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
 	unsigned int pipe;
 
+	/*
+	 * Rate-limit control transfers for devices with fragile firmware.
+	 * The Razer Kiyo Pro locks up under sustained rapid control
+	 * transfers (hundreds without delay), crashing the xHCI controller.
+	 * Throttle in this low-level function to cover all callers,
+	 * including uvc_set_video_ctrl() which bypasses uvc_query_ctrl().
+	 */
+	if (dev->quirks & UVC_QUIRK_CTRL_THROTTLE) {
+		unsigned long min_interval = msecs_to_jiffies(50);
+
+		if (dev->last_ctrl_jiffies &&
+		    time_before(jiffies,
+				dev->last_ctrl_jiffies + min_interval)) {
+			unsigned long wait = dev->last_ctrl_jiffies +
+					     min_interval - jiffies;
+			msleep(jiffies_to_msecs(wait));
+		}
+		dev->last_ctrl_jiffies = jiffies;
+	}
+
 	pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
 			      : usb_sndctrlpipe(dev->udev, 0);
 	type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 757254f..31f2af5 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -78,6 +78,7 @@
 #define UVC_QUIRK_INVALID_DEVICE_SOF	0x00010000
 #define UVC_QUIRK_MJPEG_NO_EOF		0x00020000
 #define UVC_QUIRK_MSXU_META		0x00040000
+#define UVC_QUIRK_CTRL_THROTTLE		0x00080000
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED		0x00000001
@@ -583,6 +584,8 @@ struct uvc_device {
 	struct usb_interface *intf;
 	unsigned long warnings;
 	u32 quirks;
+	/* UVC control transfer throttling (UVC_QUIRK_CTRL_THROTTLE) */
+	unsigned long last_ctrl_jiffies;
 	int intfnum;
 	char name[32];
 
-- 
2.43.0

[PATCH v8 2/2] media: uvcvideo: add Razer Kiyo Pro to device info table

[JP Hein]

Add a device entry for the Razer Kiyo Pro (1532:0e05) with quirks to
work around firmware bugs that crash the xHCI host controller:

  UVC_QUIRK_CTRL_THROTTLE   - rate-limit control transfers to prevent
                               firmware lockup under sustained load
  UVC_QUIRK_DISABLE_AUTOSUSPEND - prevent runtime suspend
  UVC_QUIRK_NO_RESET_RESUME - skip post-reset reinitialization

The firmware (v1.5.0.1) has two failure modes: it stalls endpoints
under rapid control transfers (~25 without delay), and it fails to
reinitialize properly after USB power state transitions. Both can
cascade into xHCI controller death, disconnecting all USB devices on
the bus.

Bug reproduced on two separate Kiyo Pro units running simultaneously,
confirming the issue is not unit-specific.

lsusb -vv:

  Bus 002 Device 002: ID 1532:0e05 Razer USA, Ltd Razer Kiyo Pro
  Device Descriptor:
    bLength                18
    bDescriptorType         1
    bcdUSB               3.20
    bDeviceClass          239 Miscellaneous Device
    bDeviceSubClass         2 [unknown]
    bDeviceProtocol         1 Interface Association
    bMaxPacketSize0         9
    idVendor           0x1532 Razer USA, Ltd
    idProduct          0x0e05 Razer Kiyo Pro
    bcdDevice            8.21
    iManufacturer           1 Razer Inc
    iProduct                2 Razer Kiyo Pro
    iSerial                 0
    bNumConfigurations      1
    Configuration Descriptor:
      bLength                 9
      bDescriptorType         2
      wTotalLength       0x05b4
      bNumInterfaces          4
      bConfigurationValue     1
      iConfiguration          0
      bmAttributes         0x80
        (Bus Powered)
      MaxPower              896mA
      Interface Association:
        bLength                 8
        bDescriptorType        11
        bFirstInterface         0
        bInterfaceCount         2
        bFunctionClass         14 Video
        bFunctionSubClass       3 Video Interface Collection
        bFunctionProtocol       0
        iFunction               0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        0
        bAlternateSetting       0
        bNumEndpoints           1
        bInterfaceClass        14 Video
        bInterfaceSubClass      1 Video Control
        bInterfaceProtocol      0
        iInterface              0
        VideoControl Interface Descriptor:
          bLength                13
          bDescriptorType        36
          bDescriptorSubtype      1 (HEADER)
          bcdUVC               1.00
          wTotalLength       0x0069
          dwClockFrequency       30.000000MHz
          bInCollection           1
          baInterfaceNr( 0)       1
        VideoControl Interface Descriptor:
          bLength                 9
          bDescriptorType        36
          bDescriptorSubtype      3 (OUTPUT_TERMINAL)
          bTerminalID             4
          wTerminalType      0x0101 USB Streaming
          bAssocTerminal          0
          bSourceID               2
          iTerminal               0
        VideoControl Interface Descriptor:
          bLength                27
          bDescriptorType        36
          bDescriptorSubtype      6 (EXTENSION_UNIT)
          bUnitID                 2
          guidExtensionCode         {2c49d16a-32b8-4485-3ea8-643a152362f2}
          bNumControls            6
          bNrInPins               1
          baSourceID( 0)          6
          bControlSize            2
          bmControls( 0)       0x3f
          bmControls( 1)       0x00
          iExtension              0
        VideoControl Interface Descriptor:
          bLength                27
          bDescriptorType        36
          bDescriptorSubtype      6 (EXTENSION_UNIT)
          bUnitID                 6
          guidExtensionCode         {23e49ed0-1178-4f31-ae52-d2fb8a8d3b48}
          bNumControls            5
          bNrInPins               1
          baSourceID( 0)          3
          bControlSize            2
          bmControls( 0)       0xff
          bmControls( 1)       0x7f
          iExtension              0
        VideoControl Interface Descriptor:
          bLength                18
          bDescriptorType        36
          bDescriptorSubtype      2 (INPUT_TERMINAL)
          bTerminalID             1
          wTerminalType      0x0201 Camera Sensor
          bAssocTerminal          0
          iTerminal               0
          wObjectiveFocalLengthMin      0
          wObjectiveFocalLengthMax      0
          wOcularFocalLength            0
          bControlSize                  3
          bmControls           0x00020a2e
            Auto-Exposure Mode
            Auto-Exposure Priority
            Exposure Time (Absolute)
            Focus (Absolute)
            Zoom (Absolute)
            PanTilt (Absolute)
            Focus, Auto
        VideoControl Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      5 (PROCESSING_UNIT)
        Warning: Descriptor too short
          bUnitID                 3
          bSourceID               1
          wMaxMultiplier          0
          bControlSize            2
          bmControls     0x0000175b
            Brightness
            Contrast
            Saturation
            Sharpness
            White Balance Temperature
            Backlight Compensation
            Gain
            Power Line Frequency
            White Balance Temperature, Auto
          iProcessing             0
          bmVideoStandards     0xff
            None
            NTSC - 525/60
            PAL - 625/50
            SECAM - 625/50
            NTSC - 625/50
            PAL - 525/60
        Endpoint Descriptor:
          bLength                 7
          bDescriptorType         5
          bEndpointAddress     0x85  EP 5 IN
          bmAttributes            3
            Transfer Type            Interrupt
            Synch Type               None
            Usage Type               Data
          wMaxPacketSize     0x0040  1x 64 bytes
          bInterval               8
          bMaxBurst               0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        1
        bAlternateSetting       0
        bNumEndpoints           0
        bInterfaceClass        14 Video
        bInterfaceSubClass      2 Video Streaming
        bInterfaceProtocol      0
        iInterface              0
        VideoStreaming Interface Descriptor:
          bLength                            17
          bDescriptorType                    36
          bDescriptorSubtype                  1 (INPUT_HEADER)
          bNumFormats                         4
          wTotalLength                   0x03e6
          bEndpointAddress                 0x81  EP 1 IN
          bmInfo                              0
          bTerminalLink                       4
          bStillCaptureMethod                 0
          bTriggerSupport                     0
          bTriggerUsage                       0
          bControlSize                        1
          bmaControls( 0)                     0
          bmaControls( 1)                     0
          bmaControls( 2)                     0
          bmaControls( 3)                     0
        VideoStreaming Interface Descriptor:
          bLength                            27
          bDescriptorType                    36
          bDescriptorSubtype                  4 (FORMAT_UNCOMPRESSED)
          bFormatIndex                        1
          bNumFrameDescriptors                4
          guidFormat                            {32595559-0000-0010-8000-00aa00389b71}
          bBitsPerPixel                      16
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 2 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                294912000
          dwMaxBitRate                294912000
          dwMaxVideoFrameBufferSize      614400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         7
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                221184000
          dwMaxBitRate                221184000
          dwMaxVideoFrameBufferSize      460800
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                        11
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                884736000
          dwMaxBitRate                884736000
          dwMaxVideoFrameBufferSize     1843200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                        13
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                1990656000
          dwMaxBitRate                1990656000
          dwMaxVideoFrameBufferSize     4147200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
        VideoStreaming Interface Descriptor:
          bLength                            11
          bDescriptorType                    36
          bDescriptorSubtype                  6 (FORMAT_MJPEG)
          bFormatIndex                        2
          bNumFrameDescriptors                4
          bFlags                              0
            Fixed-size samples: No
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 1 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                294912000
          dwMaxBitRate                294912000
          dwMaxVideoFrameBufferSize      614400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                         7
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                221184000
          dwMaxBitRate                221184000
          dwMaxVideoFrameBufferSize      460800
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                        11
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                884736000
          dwMaxBitRate                884736000
          dwMaxVideoFrameBufferSize     1843200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  7 (FRAME_MJPEG)
          bFrameIndex                        13
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                1990656000
          dwMaxBitRate                1990656000
          dwMaxVideoFrameBufferSize     4147200
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
        VideoStreaming Interface Descriptor:
          bLength                            28
          bDescriptorType                    36
          bDescriptorSubtype                 16 (FORMAT_FRAME_BASED)
          bFormatIndex                        3
          bNumFrameDescriptors                4
          guidFormat                            {34363248-0000-0010-8000-00aa00389b71}
          bBitsPerPixel                      16
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 2 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
          bVariableSize                     1
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                         9
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                        15
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                 17 (FRAME_FRAME_BASED)
          bFrameIndex                        17
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                251658240
          dwMaxBitRate                503316480
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwBytesPerLine                      0
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
        VideoStreaming Interface Descriptor:
          bLength                            27
          bDescriptorType                    36
          bDescriptorSubtype                  4 (FORMAT_UNCOMPRESSED)
          bFormatIndex                        4
          bNumFrameDescriptors                4
          guidFormat                            {3231564e-0000-0010-8000-00aa00389b71}
          bBitsPerPixel                      12
          bDefaultFrameIndex                  1
          bAspectRatioX                       0
          bAspectRatioY                       0
          bmInterlaceFlags                 0x00
            Interlaced stream or variable: No
            Fields per frame: 2 fields
            Field 1 first: No
            Field pattern: Field 1 only
          bCopyProtect                        0
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         1
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           480
          dwMinBitRate                221184000
          dwMaxBitRate                221184000
          dwMaxVideoFrameBufferSize      460800
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         2
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                            640
          wHeight                           360
          dwMinBitRate                165888000
          dwMaxBitRate                165888000
          dwMaxVideoFrameBufferSize      345600
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         3
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1280
          wHeight                           720
          dwMinBitRate                663552000
          dwMaxBitRate                663552000
          dwMaxVideoFrameBufferSize     1382400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                            54
          bDescriptorType                    36
          bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
          bFrameIndex                         4
          bmCapabilities                   0x00
            Still image unsupported
          wWidth                           1920
          wHeight                          1080
          dwMinBitRate                1492992000
          dwMaxBitRate                1492992000
          dwMaxVideoFrameBufferSize     3110400
          dwDefaultFrameInterval         166666
          bFrameIntervalType                  7
          dwFrameInterval( 0)            166666
          dwFrameInterval( 1)            333333
          dwFrameInterval( 2)            416666
          dwFrameInterval( 3)            500000
          dwFrameInterval( 4)            666666
          dwFrameInterval( 5)           1000000
          dwFrameInterval( 6)           2000000
        VideoStreaming Interface Descriptor:
          bLength                             6
          bDescriptorType                    36
          bDescriptorSubtype                 13 (COLORFORMAT)
          bColorPrimaries                     1 (BT.709,sRGB)
          bTransferCharacteristics            1 (BT.709)
          bMatrixCoefficients                 4 (SMPTE 170M (BT.601))
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        1
        bAlternateSetting       1
        bNumEndpoints           1
        bInterfaceClass        14 Video
        bInterfaceSubClass      2 Video Streaming
        bInterfaceProtocol      0
        iInterface              0
        Endpoint Descriptor:
          bLength                 7
          bDescriptorType         5
          bEndpointAddress     0x81  EP 1 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0400  1x 1024 bytes
          bInterval               1
          bMaxBurst               0
          Mult                    2
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        1
        bAlternateSetting       2
        bNumEndpoints           1
        bInterfaceClass        14 Video
        bInterfaceSubClass      2 Video Streaming
        bInterfaceProtocol      0
        iInterface              0
        Endpoint Descriptor:
          bLength                 7
          bDescriptorType         5
          bEndpointAddress     0x81  EP 1 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0400  1x 1024 bytes
          bInterval               1
          bMaxBurst              10
          Mult                    2
      Interface Association:
        bLength                 8
        bDescriptorType        11
        bFirstInterface         2
        bInterfaceCount         2
        bFunctionClass          1 Audio
        bFunctionSubClass       2 Streaming
        bFunctionProtocol       0
        iFunction               0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        2
        bAlternateSetting       0
        bNumEndpoints           0
        bInterfaceClass         1 Audio
        bInterfaceSubClass      1 Control Device
        bInterfaceProtocol      0
        iInterface              0
        AudioControl Interface Descriptor:
          bLength                 9
          bDescriptorType        36
          bDescriptorSubtype      1 (HEADER)
          bcdADC               1.00
          wTotalLength       0x0026
          bInCollection           1
          baInterfaceNr(0)        3
        AudioControl Interface Descriptor:
          bLength                12
          bDescriptorType        36
          bDescriptorSubtype      2 (INPUT_TERMINAL)
          bTerminalID             1
          wTerminalType      0x0201 Microphone
          bAssocTerminal          0
          bNrChannels             2
          wChannelConfig     0x0003
            Left Front (L)
            Right Front (R)
          iChannelNames           0
          iTerminal               0
        AudioControl Interface Descriptor:
          bLength                 9
          bDescriptorType        36
          bDescriptorSubtype      3 (OUTPUT_TERMINAL)
          bTerminalID             3
          wTerminalType      0x0101 USB Streaming
          bAssocTerminal          0
          bSourceID               5
          iTerminal               0
        AudioControl Interface Descriptor:
          bLength                 8
          bDescriptorType        36
          bDescriptorSubtype      6 (FEATURE_UNIT)
          bUnitID                 5
          bSourceID               1
          bControlSize            1
          bmaControls(0)       0x03
            Mute Control
            Volume Control
          iFeature                0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       0
        bNumEndpoints           0
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       1
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        48000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x00c4  1x 196 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       2
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        16000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0044  1x 68 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       3
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        24000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0064  1x 100 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
      Interface Descriptor:
        bLength                 9
        bDescriptorType         4
        bInterfaceNumber        3
        bAlternateSetting       4
        bNumEndpoints           1
        bInterfaceClass         1 Audio
        bInterfaceSubClass      2 Streaming
        bInterfaceProtocol      0
        iInterface              0
        AudioStreaming Interface Descriptor:
          bLength                 7
          bDescriptorType        36
          bDescriptorSubtype      1 (AS_GENERAL)
          bTerminalLink           3
          bDelay                  2 frames
          wFormatTag         0x0001 PCM
        AudioStreaming Interface Descriptor:
          bLength                11
          bDescriptorType        36
          bDescriptorSubtype      2 (FORMAT_TYPE)
          bFormatType             1 (FORMAT_TYPE_I)
          bNrChannels             2
          bSubframeSize           2
          bBitResolution         16
          bSamFreqType            1 Discrete
          tSamFreq[ 0]        32000
        Endpoint Descriptor:
          bLength                 9
          bDescriptorType         5
          bEndpointAddress     0x82  EP 2 IN
          bmAttributes            5
            Transfer Type            Isochronous
            Synch Type               Asynchronous
            Usage Type               Data
          wMaxPacketSize     0x0084  1x 132 bytes
          bInterval               4
          bRefresh                0
          bSynchAddress           0
          bMaxBurst               0
          AudioStreaming Endpoint Descriptor:
            bLength                 7
            bDescriptorType        37
            bDescriptorSubtype      1 (EP_GENERAL)
            bmAttributes         0x01
              Sampling Frequency
            bLockDelayUnits         0 Undefined
            wLockDelay         0x0000
  Binary Object Store Descriptor:
    bLength                 5
    bDescriptorType        15
    wTotalLength       0x0016
    bNumDeviceCaps          2
    USB 2.0 Extension Device Capability:
      bLength                 7
      bDescriptorType        16
      bDevCapabilityType      2
      bmAttributes   0x00000006
        BESL Link Power Management (LPM) Supported
    SuperSpeed USB Device Capability:
      bLength                10
      bDescriptorType        16
      bDevCapabilityType      3
      bmAttributes         0x00
      wSpeedsSupported   0x000e
        Device can operate at Full Speed (12Mbps)
        Device can operate at High Speed (480Mbps)
        Device can operate at SuperSpeed (5Gbps)
      bFunctionalitySupport   2
        Lowest fully-functional device speed is High Speed (480Mbps)
      bU1DevExitLat          10 micro seconds
      bU2DevExitLat         256 micro seconds
  Device Status:     0x0000
    (Bus Powered)

Signed-off-by: JP Hein <jp@jphein.com>
---
 drivers/media/usb/uvc/uvc_driver.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 775bede..9b6df8e 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2880,6 +2880,22 @@ static const struct usb_device_id uvc_ids[] = {
 	  .bInterfaceSubClass	= 1,
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+
+	/*
+	 * Razer Kiyo Pro -- firmware crashes under rapid control transfers
+	 * and on LPM/autosuspend resume, cascading into xHCI controller
+	 * death that disconnects all USB devices on the bus.
+	 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1532,
+	  .idProduct		= 0x0e05,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_CTRL_THROTTLE
+					| UVC_QUIRK_DISABLE_AUTOSUSPEND
+					| UVC_QUIRK_NO_RESET_RESUME) },
 	/* Kurokesu C1 PRO */
 	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
 				| USB_DEVICE_ID_MATCH_INT_INFO,
-- 
2.43.0