* [PATCH v6 1/5] media: uvcvideo: Ignore empty TS packets
2023-03-09 12:55 [PATCH v6 0/5] uvcvideo: Fixes for hw timestamping Ricardo Ribalda
@ 2023-03-09 12:55 ` Ricardo Ribalda
2023-03-10 1:57 ` Sergey Senozhatsky
2023-03-09 12:55 ` [PATCH v6 2/5] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922 Ricardo Ribalda
` (3 subsequent siblings)
4 siblings, 1 reply; 9+ messages in thread
From: Ricardo Ribalda @ 2023-03-09 12:55 UTC (permalink / raw)
To: Mauro Carvalho Chehab, Laurent Pinchart
Cc: linux-media, Ricardo Ribalda, Sergey Senozhatsky, linux-kernel,
hn.chen
Some SunplusIT cameras took a borderline interpretation of the UVC 1.5
standard, and fill the PTS and SCR fields with invalid data if the
package does not contain data.
"STC must be captured when the first video data of a video frame is put
on the USB bus."
Eg:
buffer: 0xa7755c00 len 000012 header:0x8c stc 00000000 sof 0000 pts 00000000
buffer: 0xa7755c00 len 000012 header:0x8c stc 00000000 sof 0000 pts 00000000
buffer: 0xa7755c00 len 000668 header:0x8c stc 73779dba sof 070c pts 7376d37a
This borderline/buggy interpretation has been implemented in a variety
of devices, from directly SunplusIT and from other OEMs that rebrand
SunplusIT products. So quirking based on VID:PID will be problematic.
All the affected modules have the following extension unit:
VideoControl Interface Descriptor:
guidExtensionCode {82066163-7050-ab49-b8cc-b3855e8d221d}
But the vendor plans to use that GUID in the future and fix the bug,
this means that we should use heuristic to figure out the broken
packets.
This patch takes care of this.
lsusb of one of the affected cameras:
Bus 001 Device 003: ID 1bcf:2a01 Sunplus Innovation Technology Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.01
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x1bcf Sunplus Innovation Technology Inc.
idProduct 0x2a01
bcdDevice 0.02
iManufacturer 1 SunplusIT Inc
iProduct 2 HanChen Wise Camera
iSerial 3 01.00.00
bNumConfigurations 1
Tested-by: HungNien Chen <hn.chen@sunplusit.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
drivers/media/usb/uvc/uvc_video.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index d4b023d4de7c..fc7f8b6fda85 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -478,6 +478,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
ktime_t time;
u16 host_sof;
u16 dev_sof;
+ u32 dev_stc;
switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
case UVC_STREAM_PTS | UVC_STREAM_SCR:
@@ -526,6 +527,23 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
if (dev_sof == stream->clock.last_sof)
return;
+ dev_stc = get_unaligned_le32(&data[header_size - 6]);
+
+ /*
+ * STC (Source Time Clock) is the clock used by the camera. The UVC 1.5
+ * standard states that it "must be captured when the first video data
+ * of a video frame is put on the USB bus".
+ * Most of the vendors, clear the `UVC_STREAM_SCR` bit when the data is
+ * not valid, other vendors always set the `UVC_STREAM_SCR` bit and
+ * expect that the driver only samples the stc if there is data on the
+ * packet.
+ * Ignore all the hardware timestamp information if there is no data
+ * and stc and sof are zero.
+ */
+ if (buf && buf->bytesused == 0 && len == header_size &&
+ dev_stc == 0 && dev_sof == 0)
+ return;
+
stream->clock.last_sof = dev_sof;
host_sof = usb_get_current_frame_number(stream->dev->udev);
@@ -564,7 +582,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
spin_lock_irqsave(&stream->clock.lock, flags);
sample = &stream->clock.samples[stream->clock.head];
- sample->dev_stc = get_unaligned_le32(&data[header_size - 6]);
+ sample->dev_stc = dev_stc;
sample->dev_sof = dev_sof;
sample->host_sof = host_sof;
sample->host_time = time;
--
2.40.0.rc0.216.gc4246ad0f0-goog-b4-0.11.0-dev-696ae
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v6 1/5] media: uvcvideo: Ignore empty TS packets
2023-03-09 12:55 ` [PATCH v6 1/5] media: uvcvideo: Ignore empty TS packets Ricardo Ribalda
@ 2023-03-10 1:57 ` Sergey Senozhatsky
0 siblings, 0 replies; 9+ messages in thread
From: Sergey Senozhatsky @ 2023-03-10 1:57 UTC (permalink / raw)
To: Ricardo Ribalda
Cc: Mauro Carvalho Chehab, Laurent Pinchart, linux-media,
Sergey Senozhatsky, linux-kernel, hn.chen
On (23/03/09 13:55), Ricardo Ribalda wrote:
> Some SunplusIT cameras took a borderline interpretation of the UVC 1.5
> standard, and fill the PTS and SCR fields with invalid data if the
> package does not contain data.
>
> "STC must be captured when the first video data of a video frame is put
> on the USB bus."
>
> Eg:
>
> buffer: 0xa7755c00 len 000012 header:0x8c stc 00000000 sof 0000 pts 00000000
> buffer: 0xa7755c00 len 000012 header:0x8c stc 00000000 sof 0000 pts 00000000
> buffer: 0xa7755c00 len 000668 header:0x8c stc 73779dba sof 070c pts 7376d37a
>
> This borderline/buggy interpretation has been implemented in a variety
> of devices, from directly SunplusIT and from other OEMs that rebrand
> SunplusIT products. So quirking based on VID:PID will be problematic.
>
> All the affected modules have the following extension unit:
> VideoControl Interface Descriptor:
> guidExtensionCode {82066163-7050-ab49-b8cc-b3855e8d221d}
>
> But the vendor plans to use that GUID in the future and fix the bug,
> this means that we should use heuristic to figure out the broken
> packets.
>
> This patch takes care of this.
>
> lsusb of one of the affected cameras:
>
> Bus 001 Device 003: ID 1bcf:2a01 Sunplus Innovation Technology Inc.
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.01
> bDeviceClass 239 Miscellaneous Device
> bDeviceSubClass 2 ?
> bDeviceProtocol 1 Interface Association
> bMaxPacketSize0 64
> idVendor 0x1bcf Sunplus Innovation Technology Inc.
> idProduct 0x2a01
> bcdDevice 0.02
> iManufacturer 1 SunplusIT Inc
> iProduct 2 HanChen Wise Camera
> iSerial 3 01.00.00
> bNumConfigurations 1
>
> Tested-by: HungNien Chen <hn.chen@sunplusit.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
[..]
> +
> + /*
> + * STC (Source Time Clock) is the clock used by the camera. The UVC 1.5
> + * standard states that it "must be captured when the first video data
> + * of a video frame is put on the USB bus".
> + * Most of the vendors, clear the `UVC_STREAM_SCR` bit when the data is
> + * not valid, other vendors always set the `UVC_STREAM_SCR` bit and
> + * expect that the driver only samples the stc if there is data on the
> + * packet.
> + * Ignore all the hardware timestamp information if there is no data
> + * and stc and sof are zero.
> + */
[..]
Thanks!
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v6 2/5] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922
2023-03-09 12:55 [PATCH v6 0/5] uvcvideo: Fixes for hw timestamping Ricardo Ribalda
2023-03-09 12:55 ` [PATCH v6 1/5] media: uvcvideo: Ignore empty TS packets Ricardo Ribalda
@ 2023-03-09 12:55 ` Ricardo Ribalda
2023-03-10 1:58 ` Sergey Senozhatsky
2023-03-09 12:55 ` [PATCH v6 3/5] media: uvcvideo: Allow hw clock updates with buffers not full Ricardo Ribalda
` (2 subsequent siblings)
4 siblings, 1 reply; 9+ messages in thread
From: Ricardo Ribalda @ 2023-03-09 12:55 UTC (permalink / raw)
To: Mauro Carvalho Chehab, Laurent Pinchart
Cc: linux-media, Ricardo Ribalda, Sergey Senozhatsky, linux-kernel,
hn.chen
Logitech C922 internal SOF does not increases at a stable rate of 1kHz.
This causes that the device_sof and the host_sof run at different rates,
breaking the clock domain conversion algorithm. Eg:
30 (6) [-] none 30 614400 B 21.245557 21.395214 34.133 fps ts mono/SoE
31 (7) [-] none 31 614400 B 21.275327 21.427246 33.591 fps ts mono/SoE
32 (0) [-] none 32 614400 B 21.304739 21.459256 34.000 fps ts mono/SoE
33 (1) [-] none 33 614400 B 21.334324 21.495274 33.801 fps ts mono/SoE
* 34 (2) [-] none 34 614400 B 21.529237 21.527297 5.130 fps ts mono/SoE
* 35 (3) [-] none 35 614400 B 21.649416 21.559306 8.321 fps ts mono/SoE
36 (4) [-] none 36 614400 B 21.678789 21.595320 34.045 fps ts mono/SoE
...
99 (3) [-] none 99 614400 B 23.542226 23.696352 33.541 fps ts mono/SoE
100 (4) [-] none 100 614400 B 23.571578 23.728404 34.069 fps ts mono/SoE
101 (5) [-] none 101 614400 B 23.601425 23.760420 33.504 fps ts mono/SoE
* 102 (6) [-] none 102 614400 B 23.798324 23.796428 5.079 fps ts mono/SoE
* 103 (7) [-] none 103 614400 B 23.916271 23.828450 8.478 fps ts mono/SoE
104 (0) [-] none 104 614400 B 23.945720 23.860479 33.957 fps ts mono/SoE
Instead of disabling completely the hardware timestamping for such
hardware we take the assumption that the packet handling jitter is
under 2ms and use the host_sof as dev_sof.
We can think of the UVC hardware clock as a system with a coarse clock
(the SOF) and a fine clock (the PTS). The coarse clock can be replaced
with a clock on the same frequency, if the jitter of such clock is
smaller than its sampling rate. That way we can save some of the
precision of the fine clock.
To probe this point we have run three experiments on the Logitech C922.
On that experiment we run the camera at 33fps and we analyse the
difference in msec between a frame and its predecessor. If we display
the histogram of that value, a thinner histogram will mean a better
meassurement. The results for:
- original hw timestamp: https://ibb.co/D1HJJ4x
- pure software timestamp: https://ibb.co/QC9MgVK
- modified hw timestamp: https://ibb.co/8s9dBdk
This bug in the camera firmware has been confirmed by the vendor.
lsusb -v
Bus 001 Device 044: ID 046d:085c Logitech, Inc. C922 Pro Stream Webcam
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x046d Logitech, Inc.
idProduct 0x085c C922 Pro Stream Webcam
bcdDevice 0.16
iManufacturer 0
iProduct 2 C922 Pro Stream Webcam
iSerial 1 80B912DF
bNumConfigurations 1
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
drivers/media/usb/uvc/uvc_driver.c | 9 +++++++++
drivers/media/usb/uvc/uvc_video.c | 8 ++++++++
drivers/media/usb/uvc/uvcvideo.h | 1 +
3 files changed, 18 insertions(+)
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 7aefa76a42b3..678a5736c9df 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2549,6 +2549,15 @@ static const struct usb_device_id uvc_ids[] = {
.bInterfaceSubClass = 1,
.bInterfaceProtocol = 0,
.driver_info = UVC_INFO_QUIRK(UVC_QUIRK_RESTORE_CTRLS_ON_INIT) },
+ /* Logitech HD Pro Webcam C922 */
+ { .match_flags = USB_DEVICE_ID_MATCH_DEVICE
+ | USB_DEVICE_ID_MATCH_INT_INFO,
+ .idVendor = 0x046d,
+ .idProduct = 0x085c,
+ .bInterfaceClass = USB_CLASS_VIDEO,
+ .bInterfaceSubClass = 1,
+ .bInterfaceProtocol = 0,
+ .driver_info = UVC_INFO_QUIRK(UVC_QUIRK_INVALID_DEVICE_SOF) },
/* Chicony CNF7129 (Asus EEE 100HE) */
{ .match_flags = USB_DEVICE_ID_MATCH_DEVICE
| USB_DEVICE_ID_MATCH_INT_INFO,
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index fc7f8b6fda85..e363a71dd190 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -547,6 +547,14 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
stream->clock.last_sof = dev_sof;
host_sof = usb_get_current_frame_number(stream->dev->udev);
+
+ /*
+ * On some devices, like the Logitech C922, the device SOF does not run
+ * at a stable rate of 1kHz. For those devices use the host SOF instead.
+ */
+ if (stream->dev->quirks & UVC_QUIRK_INVALID_DEVICE_SOF)
+ dev_sof = host_sof;
+
time = uvc_video_get_time();
/*
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 9a596c8d894a..07b2fdb80adf 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -73,6 +73,7 @@
#define UVC_QUIRK_FORCE_Y8 0x00000800
#define UVC_QUIRK_FORCE_BPP 0x00001000
#define UVC_QUIRK_WAKE_AUTOSUSPEND 0x00002000
+#define UVC_QUIRK_INVALID_DEVICE_SOF 0x00004000
/* Format flags */
#define UVC_FMT_FLAG_COMPRESSED 0x00000001
--
2.40.0.rc0.216.gc4246ad0f0-goog-b4-0.11.0-dev-696ae
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v6 2/5] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922
2023-03-09 12:55 ` [PATCH v6 2/5] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922 Ricardo Ribalda
@ 2023-03-10 1:58 ` Sergey Senozhatsky
0 siblings, 0 replies; 9+ messages in thread
From: Sergey Senozhatsky @ 2023-03-10 1:58 UTC (permalink / raw)
To: Ricardo Ribalda
Cc: Mauro Carvalho Chehab, Laurent Pinchart, linux-media,
Sergey Senozhatsky, linux-kernel, hn.chen
On (23/03/09 13:55), Ricardo Ribalda wrote:
[..]
> Bus 001 Device 044: ID 046d:085c Logitech, Inc. C922 Pro Stream Webcam
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 239 Miscellaneous Device
> bDeviceSubClass 2
> bDeviceProtocol 1 Interface Association
> bMaxPacketSize0 64
> idVendor 0x046d Logitech, Inc.
> idProduct 0x085c C922 Pro Stream Webcam
> bcdDevice 0.16
> iManufacturer 0
> iProduct 2 C922 Pro Stream Webcam
> iSerial 1 80B912DF
> bNumConfigurations 1
>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v6 3/5] media: uvcvideo: Allow hw clock updates with buffers not full
2023-03-09 12:55 [PATCH v6 0/5] uvcvideo: Fixes for hw timestamping Ricardo Ribalda
2023-03-09 12:55 ` [PATCH v6 1/5] media: uvcvideo: Ignore empty TS packets Ricardo Ribalda
2023-03-09 12:55 ` [PATCH v6 2/5] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922 Ricardo Ribalda
@ 2023-03-09 12:55 ` Ricardo Ribalda
2023-03-10 2:20 ` Sergey Senozhatsky
2023-03-09 12:55 ` [PATCH v6 4/5] media: uvcvideo: Refactor clock circular buffer Ricardo Ribalda
2023-03-09 12:55 ` [PATCH v6 5/5] media: uvcvideo: Fix hw timestamp handling for slow FPS Ricardo Ribalda
4 siblings, 1 reply; 9+ messages in thread
From: Ricardo Ribalda @ 2023-03-09 12:55 UTC (permalink / raw)
To: Mauro Carvalho Chehab, Laurent Pinchart
Cc: linux-media, Ricardo Ribalda, Sergey Senozhatsky, linux-kernel,
hn.chen
With UVC 1.5 we get as little as one clock sample per frame. Which means
that it takes 32 frames to move from the software timestamp to the
hardware timestamp method.
This results in abrupt changes in the timestamping after 32 frames (~1
second), resulting in noticeable artifacts when used for encoding.
With this patch we modify the update algorithm to work with whatever
amount of values are available.
Tested-by: HungNien Chen <hn.chen@sunplusit.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
drivers/media/usb/uvc/uvc_video.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index e363a71dd190..d5fb0c1339a3 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -754,10 +754,10 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
spin_lock_irqsave(&clock->lock, flags);
- if (clock->count < clock->size)
+ if (clock->count < 2)
goto done;
- first = &clock->samples[clock->head];
+ first = &clock->samples[(clock->head - clock->count) % clock->size];
last = &clock->samples[(clock->head - 1) % clock->size];
/* First step, PTS to SOF conversion. */
@@ -772,6 +772,15 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
if (y2 < y1)
y2 += 2048 << 16;
+ /*
+ * Have at least 1/4 of a second of timestamps before we
+ * try to do any calculation. Otherwise we do not have enough
+ * precision. This value was determined by running Android CTS
+ * on different devices.
+ */
+ if ((y2 - y1) < (256 << 16))
+ goto done;
+
y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2
- (u64)y2 * (u64)x1;
y = div_u64(y, x2 - x1);
--
2.40.0.rc0.216.gc4246ad0f0-goog-b4-0.11.0-dev-696ae
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v6 3/5] media: uvcvideo: Allow hw clock updates with buffers not full
2023-03-09 12:55 ` [PATCH v6 3/5] media: uvcvideo: Allow hw clock updates with buffers not full Ricardo Ribalda
@ 2023-03-10 2:20 ` Sergey Senozhatsky
0 siblings, 0 replies; 9+ messages in thread
From: Sergey Senozhatsky @ 2023-03-10 2:20 UTC (permalink / raw)
To: Ricardo Ribalda
Cc: Mauro Carvalho Chehab, Laurent Pinchart, linux-media,
Sergey Senozhatsky, linux-kernel, hn.chen
On (23/03/09 13:55), Ricardo Ribalda wrote:
[..]
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -754,10 +754,10 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
>
> spin_lock_irqsave(&clock->lock, flags);
>
> - if (clock->count < clock->size)
> + if (clock->count < 2)
> goto done;
>
> - first = &clock->samples[clock->head];
> + first = &clock->samples[(clock->head - clock->count) % clock->size];
This looks like a significant change: `rb->head` and `rb->head - INT`
are quite different things. May I ask for some clarifications?
[..]
> + /*
> + * Have at least 1/4 of a second of timestamps before we
> + * try to do any calculation. Otherwise we do not have enough
> + * precision. This value was determined by running Android CTS
> + * on different devices.
> + */
> + if ((y2 - y1) < (256 << 16))
256 << 16 is 1/4 of a second?
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v6 4/5] media: uvcvideo: Refactor clock circular buffer
2023-03-09 12:55 [PATCH v6 0/5] uvcvideo: Fixes for hw timestamping Ricardo Ribalda
` (2 preceding siblings ...)
2023-03-09 12:55 ` [PATCH v6 3/5] media: uvcvideo: Allow hw clock updates with buffers not full Ricardo Ribalda
@ 2023-03-09 12:55 ` Ricardo Ribalda
2023-03-09 12:55 ` [PATCH v6 5/5] media: uvcvideo: Fix hw timestamp handling for slow FPS Ricardo Ribalda
4 siblings, 0 replies; 9+ messages in thread
From: Ricardo Ribalda @ 2023-03-09 12:55 UTC (permalink / raw)
To: Mauro Carvalho Chehab, Laurent Pinchart
Cc: linux-media, Ricardo Ribalda, Sergey Senozhatsky, linux-kernel,
hn.chen
Isolate all the changes related to the clock circular buffer to its own
function, that way we can make changes easier to the buffer logic.
Also simplify the lock, by removing the circular buffer clock handling
from uvc_video_clock_decode().
And now that we are at it, unify the API of the clock functions.
Tested-by: HungNien Chen <hn.chen@sunplusit.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
drivers/media/usb/uvc/uvc_video.c | 82 ++++++++++++++++++---------------------
1 file changed, 37 insertions(+), 45 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index d5fb0c1339a3..0bb862e8c803 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -466,19 +466,28 @@ static inline ktime_t uvc_video_get_time(void)
return ktime_get_real();
}
+static void uvc_video_clock_add_sample(struct uvc_clock *clock,
+ const struct uvc_clock_sample *sample)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&clock->lock, flags);
+
+ memcpy(&clock->samples[clock->head], sample, sizeof(*sample));
+ clock->head = (clock->head + 1) % clock->size;
+ clock->count = min(clock->count + 1, clock->size);
+
+ spin_unlock_irqrestore(&clock->lock, flags);
+}
+
static void
uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
const u8 *data, int len)
{
- struct uvc_clock_sample *sample;
+ struct uvc_clock_sample sample;
unsigned int header_size;
bool has_pts = false;
bool has_scr = false;
- unsigned long flags;
- ktime_t time;
- u16 host_sof;
- u16 dev_sof;
- u32 dev_stc;
switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
case UVC_STREAM_PTS | UVC_STREAM_SCR:
@@ -523,11 +532,11 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
* all the data packets of the same frame contains the same SOF. In that
* case only the first one will match the host_sof.
*/
- dev_sof = get_unaligned_le16(&data[header_size - 2]);
- if (dev_sof == stream->clock.last_sof)
+ sample.dev_sof = get_unaligned_le16(&data[header_size - 2]);
+ if (sample.dev_sof == stream->clock.last_sof)
return;
- dev_stc = get_unaligned_le32(&data[header_size - 6]);
+ sample.dev_stc = get_unaligned_le32(&data[header_size - 6]);
/*
* STC (Source Time Clock) is the clock used by the camera. The UVC 1.5
@@ -541,21 +550,21 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
* and stc and sof are zero.
*/
if (buf && buf->bytesused == 0 && len == header_size &&
- dev_stc == 0 && dev_sof == 0)
+ sample.dev_stc == 0 && sample.dev_sof == 0)
return;
- stream->clock.last_sof = dev_sof;
+ stream->clock.last_sof = sample.dev_sof;
- host_sof = usb_get_current_frame_number(stream->dev->udev);
+ sample.host_sof = usb_get_current_frame_number(stream->dev->udev);
/*
* On some devices, like the Logitech C922, the device SOF does not run
* at a stable rate of 1kHz. For those devices use the host SOF instead.
*/
if (stream->dev->quirks & UVC_QUIRK_INVALID_DEVICE_SOF)
- dev_sof = host_sof;
+ sample.dev_sof = sample.host_sof;
- time = uvc_video_get_time();
+ sample.host_time = uvc_video_get_time();
/*
* The UVC specification allows device implementations that can't obtain
@@ -578,46 +587,29 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
* the 8 LSBs of the delta are kept.
*/
if (stream->clock.sof_offset == (u16)-1) {
- u16 delta_sof = (host_sof - dev_sof) & 255;
+ u16 delta_sof = (sample.host_sof - sample.dev_sof) & 255;
if (delta_sof >= 10)
stream->clock.sof_offset = delta_sof;
else
stream->clock.sof_offset = 0;
}
- dev_sof = (dev_sof + stream->clock.sof_offset) & 2047;
-
- spin_lock_irqsave(&stream->clock.lock, flags);
-
- sample = &stream->clock.samples[stream->clock.head];
- sample->dev_stc = dev_stc;
- sample->dev_sof = dev_sof;
- sample->host_sof = host_sof;
- sample->host_time = time;
-
- /* Update the sliding window head and count. */
- stream->clock.head = (stream->clock.head + 1) % stream->clock.size;
+ sample.dev_sof = (sample.dev_sof + stream->clock.sof_offset) & 2047;
+ sample.dev_stc = get_unaligned_le32(&data[header_size - 6]);
- if (stream->clock.count < stream->clock.size)
- stream->clock.count++;
-
- spin_unlock_irqrestore(&stream->clock.lock, flags);
+ uvc_video_clock_add_sample(&stream->clock, &sample);
}
-static void uvc_video_clock_reset(struct uvc_streaming *stream)
+static void uvc_video_clock_reset(struct uvc_clock *clock)
{
- struct uvc_clock *clock = &stream->clock;
-
clock->head = 0;
clock->count = 0;
clock->last_sof = -1;
clock->sof_offset = -1;
}
-static int uvc_video_clock_init(struct uvc_streaming *stream)
+static int uvc_video_clock_init(struct uvc_clock *clock)
{
- struct uvc_clock *clock = &stream->clock;
-
spin_lock_init(&clock->lock);
clock->size = 32;
@@ -626,15 +618,15 @@ static int uvc_video_clock_init(struct uvc_streaming *stream)
if (clock->samples == NULL)
return -ENOMEM;
- uvc_video_clock_reset(stream);
+ uvc_video_clock_reset(clock);
return 0;
}
-static void uvc_video_clock_cleanup(struct uvc_streaming *stream)
+static void uvc_video_clock_cleanup(struct uvc_clock *clock)
{
- kfree(stream->clock.samples);
- stream->clock.samples = NULL;
+ kfree(clock->samples);
+ clock->samples = NULL;
}
/*
@@ -2106,7 +2098,7 @@ int uvc_video_resume(struct uvc_streaming *stream, int reset)
stream->frozen = 0;
- uvc_video_clock_reset(stream);
+ uvc_video_clock_reset(&stream->clock);
if (!uvc_queue_streaming(&stream->queue))
return 0;
@@ -2255,7 +2247,7 @@ int uvc_video_start_streaming(struct uvc_streaming *stream)
{
int ret;
- ret = uvc_video_clock_init(stream);
+ ret = uvc_video_clock_init(&stream->clock);
if (ret < 0)
return ret;
@@ -2273,7 +2265,7 @@ int uvc_video_start_streaming(struct uvc_streaming *stream)
error_video:
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
error_commit:
- uvc_video_clock_cleanup(stream);
+ uvc_video_clock_cleanup(&stream->clock);
return ret;
}
@@ -2301,5 +2293,5 @@ void uvc_video_stop_streaming(struct uvc_streaming *stream)
usb_clear_halt(stream->dev->udev, pipe);
}
- uvc_video_clock_cleanup(stream);
+ uvc_video_clock_cleanup(&stream->clock);
}
--
2.40.0.rc0.216.gc4246ad0f0-goog-b4-0.11.0-dev-696ae
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v6 5/5] media: uvcvideo: Fix hw timestamp handling for slow FPS
2023-03-09 12:55 [PATCH v6 0/5] uvcvideo: Fixes for hw timestamping Ricardo Ribalda
` (3 preceding siblings ...)
2023-03-09 12:55 ` [PATCH v6 4/5] media: uvcvideo: Refactor clock circular buffer Ricardo Ribalda
@ 2023-03-09 12:55 ` Ricardo Ribalda
4 siblings, 0 replies; 9+ messages in thread
From: Ricardo Ribalda @ 2023-03-09 12:55 UTC (permalink / raw)
To: Mauro Carvalho Chehab, Laurent Pinchart
Cc: linux-media, Ricardo Ribalda, Sergey Senozhatsky, linux-kernel,
hn.chen
In UVC 1.5 we get a single clock value per frame. With the current
buffer size of 32, FPS slowers than 32 might roll-over twice.
The current code cannot handle two roll-over and provide invalid
timestamps.
Revome all the samples from the circular buffer that are more than two
rollovers old, so the algorithm always provides good timestamps.
Note that we are removing values that are more than one second old,
which means that there is enough distance between the two points that
we use for the interpolation to provide good values.
Tested-by: HungNien Chen <hn.chen@sunplusit.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
drivers/media/usb/uvc/uvc_video.c | 15 +++++++++++++++
drivers/media/usb/uvc/uvcvideo.h | 1 +
2 files changed, 16 insertions(+)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 0bb862e8c803..6f2bb0dc991c 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -473,6 +473,20 @@ static void uvc_video_clock_add_sample(struct uvc_clock *clock,
spin_lock_irqsave(&clock->lock, flags);
+ /* Delete last overflows */
+ if (clock->head == clock->last_sof_overflow)
+ clock->last_sof_overflow = -1;
+
+ /* Handle overflows */
+ if (clock->count > 0 && clock->last_sof > sample->dev_sof) {
+ /* Remove data from the last^2 overflows */
+ if (clock->last_sof_overflow != -1)
+ clock->count = (clock->head - clock->last_sof_overflow)
+ % clock->count;
+ clock->last_sof_overflow = clock->head;
+ }
+
+ /* Add sample */
memcpy(&clock->samples[clock->head], sample, sizeof(*sample));
clock->head = (clock->head + 1) % clock->size;
clock->count = min(clock->count + 1, clock->size);
@@ -605,6 +619,7 @@ static void uvc_video_clock_reset(struct uvc_clock *clock)
clock->head = 0;
clock->count = 0;
clock->last_sof = -1;
+ clock->last_sof_overflow = -1;
clock->sof_offset = -1;
}
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 07b2fdb80adf..bf9f5162b833 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -499,6 +499,7 @@ struct uvc_streaming {
unsigned int head;
unsigned int count;
unsigned int size;
+ unsigned int last_sof_overflow;
u16 last_sof;
u16 sof_offset;
--
2.40.0.rc0.216.gc4246ad0f0-goog-b4-0.11.0-dev-696ae
^ permalink raw reply related [flat|nested] 9+ messages in thread