[PATCH v5] usb: Reduce 'set_address' command timeout with a new quirk

Hardik Gajjar
2023-10-25T14:13:37Z

This patch introduces a new USB quirk, USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT,
which modifies the timeout value for the 'set_address' command. The
standard timeout for this command is 5000 ms, as recommended in the USB
3.2 specification (section 9.2.6.1).

However, certain scenarios, such as connecting devices through an APTIV hub,
can lead to timeout errors when the device enumerates as full speed initially
and later switches to high speed during chirp negotiation.

In such cases, USB analyzer logs reveal that the bus suspends for 5 seconds
due to incorrect chirp parsing and resumes only after two consecutive
timeout errors trigger a hub driver reset.

Packet(54) Dir(?) Full Speed J(997.100 us) Idle( 2.850 us)
_______| Time Stamp(28 . 105 910 682)
_______|_________________________________________________________________Ch0
Packet(55) Dir(?) Full Speed J(997.118 us) Idle( 2.850 us)
_______| Time Stamp(28 . 106 910 632)
_______|_________________________________________________________________Ch0
Packet(56) Dir(?) Full Speed J(399.650 us) Idle(222.582 us)
_______| Time Stamp(28 . 107 910 600)
_______|_________________________________________________________________Ch0
Packet(57) Dir Chirp J( 23.955 ms) Idle(115.169 ms)
_______| Time Stamp(28 . 108 532 832)
_______|_________________________________________________________________Ch0
Packet(58) Dir(?) Full Speed J (Suspend)( 5.347 sec) Idle( 5.366 us)
_______| Time Stamp(28 . 247 657 600)
_______|_________________________________________________________________Ch0

This 5-second delay in device enumeration is undesirable, particularly in
automotive applications where quick enumeration is crucial
(ideally within 3 seconds).

The newly introduced quirks provide the flexibility to align with a
3-second time limit, as required in specific contexts like automotive
applications.

By reducing the 'set_address' command timeout to 500 ms, the
system can respond more swiftly to errors, initiate rapid recovery, and
ensure efficient device enumeration. This change is vital for scenarios
where rapid smartphone enumeration and screen projection are essential.
To use the quirk, please write "vendor_id:product_id:p" to
/sys/bus/usb/drivers/hub/module/parameter/quirks

For example,
echo "0x2c48:0x0132:p" > /sys/bus/usb/drivers/hub/module/parameter/quirks"

Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
---
changes since version 1:
- implement quirk instead of new API in xhci driver

changes since version 2:
- Add documentation for the new quirk.
- Define the timeout unit in milliseconds in variable names and function arguments.
- Change the xHCI command timeout from HZ (jiffies) to milliseconds.
- Add APTIV usb hub vendor and product ID in device quirk list
- Adding some other comments for clarity

Changes since version 3:
- Add some comments for clarity.
- Minor indentation and sequence change.

Changes since version 4:
- Changing the USB specification reference to version 3.2.
- Enhancing the commit message to provide more details about the technical issue.
- Improving the structure of function comments.
---
.../admin-guide/kernel-parameters.txt | 3 +++
drivers/usb/core/hub.c | 21 +++++++++++++++++--
drivers/usb/core/quirks.c | 6 ++++++
drivers/usb/host/xhci-mem.c | 2 ++
drivers/usb/host/xhci-ring.c | 11 +++++-----
drivers/usb/host/xhci.c | 21 +++++++++++++------
drivers/usb/host/xhci.h | 9 ++++++--
include/linux/usb/hcd.h | 5 +++--
include/linux/usb/quirks.h | 3 +++
9 files changed, 64 insertions(+), 17 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0a1731a0f0ef..3c03f23bd5d5 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6817,6 +6817,9 @@
pause after every control message);
o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra
delay after resetting its port);
+ p = USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT (Timeout
+ of set_address command reducing from
+ 5000 ms to 500 ms)
Example: quirks=0781:5580:bk,0a5c:5834:gij

usbhid.mousepoll=
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 3c54b218301c..3594eeb892ac 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -54,6 +54,18 @@
#define USB_TP_TRANSMISSION_DELAY_MAX 65535 /* ns */
#define USB_PING_RESPONSE_TIME 400 /* ns */

+/*
+ * address device command timeout 5000 ms is recommended in
+ * USB 3.2 spec, section 9.2.6.1
+ */
+#define USB_DEFAULT_ADDR_DEVICE_TIMEOUT_MS 5000 /* ms */
+
+/*
+ * address device command timeout will be 500 ms when
+ * USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT enable.
+ */
+#define USB_SHORT_ADDR_DEVICE_TIMEOUT_MS 500 /* ms */
+
/* Protect struct usb_device->state and ->children members
* Note: Both are also protected by ->dev.sem, except that ->state can
* change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
@@ -4626,7 +4638,12 @@ EXPORT_SYMBOL_GPL(usb_ep0_reinit);
static int hub_set_address(struct usb_device *udev, int devnum)
{
int retval;
+ unsigned int timeout_ms = USB_DEFAULT_ADDR_DEVICE_TIMEOUT_MS;
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+ struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
+
+ if (hub->hdev->quirks & USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT)
+ timeout_ms = USB_SHORT_ADDR_DEVICE_TIMEOUT_MS;

/*
* The host controller will choose the device address,
@@ -4639,11 +4656,11 @@ static int hub_set_address(struct usb_device *udev, int devnum)
if (udev->state != USB_STATE_DEFAULT)
return -EINVAL;
if (hcd->driver->address_device)
- retval = hcd->driver->address_device(hcd, udev);
+ retval = hcd->driver->address_device(hcd, udev, timeout_ms);
else
retval = usb_control_msg(udev, usb_sndaddr0pipe(),
USB_REQ_SET_ADDRESS, 0, devnum, 0,
- NULL, 0, USB_CTRL_SET_TIMEOUT);
+ NULL, 0, timeout_ms);
if (retval == 0) {
update_devnum(udev, devnum);
/* Device now using proper address. */
diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 15e9bd180a1d..863e7fe24157 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -138,6 +138,9 @@ static int quirks_param_set(const char *value, const struct kernel_param *kp)
case 'o':
flags |= USB_QUIRK_HUB_SLOW_RESET;
break;
+ case 'p':
+ flags |= USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT;
+ break;
/* Ignore unrecognized flag characters */
}
}
@@ -527,6 +530,9 @@ static const struct usb_device_id usb_quirk_list[] = {

{ USB_DEVICE(0x2386, 0x350e), .driver_info = USB_QUIRK_NO_LPM },

+ /* APTIV AUTOMOTIVE HUB */
+ { USB_DEVICE(0x2c48, 0x0132), .driver_info = USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT },
+
/* DJI CineSSD */
{ USB_DEVICE(0x2ca3, 0x0031), .driver_info = USB_QUIRK_NO_LPM },

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 8714ab5bf04d..4a286136d1a8 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1729,6 +1729,8 @@ struct xhci_command *xhci_alloc_command(struct xhci_hcd *xhci,
}

command->status = 0;
+ /* set default timeout to 5000 ms */
+ command->timeout_ms = XHCI_CMD_DEFAULT_TIMEOUT_MS;
INIT_LIST_HEAD(&command->cmd_list);
return command;
}
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 1dde53f6eb31..8f36c2914938 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -366,9 +366,10 @@ void xhci_ring_cmd_db(struct xhci_hcd *xhci)
readl(&xhci->dba->doorbell[0]);
}

-static bool xhci_mod_cmd_timer(struct xhci_hcd *xhci, unsigned long delay)
+static bool xhci_mod_cmd_timer(struct xhci_hcd *xhci)
{
- return mod_delayed_work(system_wq, &xhci->cmd_timer, delay);
+ return mod_delayed_work(system_wq, &xhci->cmd_timer,
+ msecs_to_jiffies(xhci->current_cmd->timeout_ms));
}

static struct xhci_command *xhci_next_queued_cmd(struct xhci_hcd *xhci)
@@ -412,7 +413,7 @@ static void xhci_handle_stopped_cmd_ring(struct xhci_hcd *xhci,
if ((xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue) &&
!(xhci->xhc_state & XHCI_STATE_DYING)) {
xhci->current_cmd = cur_cmd;
- xhci_mod_cmd_timer(xhci, XHCI_CMD_DEFAULT_TIMEOUT);
+ xhci_mod_cmd_timer(xhci);
xhci_ring_cmd_db(xhci);
}
}
@@ -1786,7 +1787,7 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
if (!list_is_singular(&xhci->cmd_list)) {
xhci->current_cmd = list_first_entry(&cmd->cmd_list,
struct xhci_command, cmd_list);
- xhci_mod_cmd_timer(xhci, XHCI_CMD_DEFAULT_TIMEOUT);
+ xhci_mod_cmd_timer(xhci);
} else if (xhci->current_cmd == cmd) {
xhci->current_cmd = NULL;
}
@@ -4301,7 +4302,7 @@ static int queue_command(struct xhci_hcd *xhci, struct xhci_command *cmd,
/* if there are no other commands queued we start the timeout timer */
if (list_empty(&xhci->cmd_list)) {
xhci->current_cmd = cmd;
- xhci_mod_cmd_timer(xhci, XHCI_CMD_DEFAULT_TIMEOUT);
+ xhci_mod_cmd_timer(xhci);
}

list_add_tail(&cmd->cmd_list, &xhci->cmd_list);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index e1b1b64a0723..0c610a853aef 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3998,11 +3998,17 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
}

/*
- * Issue an Address Device command and optionally send a corresponding
- * SetAddress request to the device.
+ * xhci_setup_device - issues an Address Device command to assign a unique
+ * USB bus address.
+ * @hcd USB host controller data structure.
+ * @udev USB dev structure representing the connected device.
+ * @setup Enum specifying setup mode: address only or with context.
+ * @timeout_ms Max wait time (ms) for the command operation to complete.
+ *
+ * Return: 0 if successful; otherwise, negative error code.
*/
static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
- enum xhci_setup_dev setup)
+ enum xhci_setup_dev setup, unsigned int timeout_ms)
{
const char *act = setup == SETUP_CONTEXT_ONLY ? "context" : "address";
unsigned long flags;
@@ -4059,6 +4065,7 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
}

command->in_ctx = virt_dev->in_ctx;
+ command->timeout_ms = timeout_ms;

slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
ctrl_ctx = xhci_get_input_control_ctx(virt_dev->in_ctx);
@@ -4185,14 +4192,16 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
return ret;
}

-static int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+static int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev,
+ unsigned int timeout_ms)
{
- return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ADDRESS);
+ return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ADDRESS, timeout_ms);
}

static int xhci_enable_device(struct usb_hcd *hcd, struct usb_device *udev)
{
- return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ONLY);
+ return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ONLY,
+ XHCI_CMD_DEFAULT_TIMEOUT_MS);
}

/*
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 7e282b4522c0..c0ff6b399769 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -818,6 +818,8 @@ struct xhci_command {
struct completion *completion;
union xhci_trb *command_trb;
struct list_head cmd_list;
+ /* xHCI command response timeout in milliseconds */
+ unsigned int timeout_ms;
};

/* drop context bitmasks */
@@ -1576,8 +1578,11 @@ struct xhci_td {
unsigned int num_trbs;
};

-/* xHCI command default timeout value */
-#define XHCI_CMD_DEFAULT_TIMEOUT (5 * HZ)
+/*
+ * xHCI command default timeout value in milliseconds.
+ * USB 3.2 spec, section 9.2.6.1
+ */
+#define XHCI_CMD_DEFAULT_TIMEOUT_MS 5000

/* command descriptor */
struct xhci_cd {
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 61d4f0b793dc..d0e19ac3ba6c 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -372,8 +372,9 @@ struct hc_driver {
* or bandwidth constraints.
*/
void (*reset_bandwidth)(struct usb_hcd *, struct usb_device *);
- /* Returns the hardware-chosen device address */
- int (*address_device)(struct usb_hcd *, struct usb_device *udev);
+ /* Set the hardware-chosen device address */
+ int (*address_device)(struct usb_hcd *, struct usb_device *udev,
+ unsigned int timeout_ms);
/* prepares the hardware to send commands to the device */
int (*enable_device)(struct usb_hcd *, struct usb_device *udev);
/* Notifies the HCD after a hub descriptor is fetched.
diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index eeb7c2157c72..0cb464e3eaf4 100644
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -72,4 +72,7 @@
/* device has endpoints that should be ignored */
#define USB_QUIRK_ENDPOINT_IGNORE BIT(15)

+/* short device address timeout */
+#define USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT BIT(16)
+
#endif /* __LINUX_USB_QUIRKS_H */
--
2.17.1