[PATCH] media/uvcvideo: add quirk for invalid dev_sof in Logitech C920

Oleksandr Natalenko
2024-03-25T14:26:24Z

Similarly to Logitech C922, C920 seems to also suffer from a firmware
bug that breaks hardware timestamping.

Add a quirk for this camera model too.

Before applying the quirk:

```
100 (4) [-] none 100 200717 B 212.919114 213.079004 33.727 fps ts mono/SoE
101 (5) [-] none 101 200889 B 213.003703 213.114996 11.822 fps ts mono/SoE
102 (6) [-] none 102 200926 B 213.035571 213.146999 31.379 fps ts mono/SoE
103 (7) [-] none 103 200839 B 213.067424 213.179003 31.394 fps ts mono/SoE
104 (0) [-] none 104 200692 B 213.293180 213.214991 4.430 fps ts mono/SoE
105 (1) [-] none 105 200937 B 213.322374 213.247001 34.254 fps ts mono/SoE
106 (2) [-] none 106 201013 B 213.352228 213.279005 33.496 fps ts mono/SoE
…
```

After applying the quirk:

```
154 (2) [-] none 154 192417 B 42.199823 42.207788 27.779 fps ts mono/SoE
155 (3) [-] none 155 192040 B 42.231834 42.239791 31.239 fps ts mono/SoE
156 (4) [-] none 156 192213 B 42.263823 42.271822 31.261 fps ts mono/SoE
157 (5) [-] none 157 191981 B 42.299824 42.303827 27.777 fps ts mono/SoE
158 (6) [-] none 158 191953 B 42.331835 42.339811 31.239 fps ts mono/SoE
159 (7) [-] none 159 191904 B 42.363824 42.371813 31.261 fps ts mono/SoE
160 (0) [-] none 160 192210 B 42.399834 42.407801 27.770 fps ts mono/SoE
```

Link: https://lore.kernel.org/lkml/5764213.DvuYhMxLoT@natalenko.name/
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Oleksandr Natalenko <oleksandr@natalenko.name>
---
drivers/media/usb/uvc/uvc_driver.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 723e6d5680c2e..444d7089885ea 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2573,7 +2573,8 @@ static const struct usb_device_id uvc_ids[] = {
.bInterfaceClass = USB_CLASS_VIDEO,
.bInterfaceSubClass = 1,
.bInterfaceProtocol = 0,
- .driver_info = UVC_INFO_QUIRK(UVC_QUIRK_RESTORE_CTRLS_ON_INIT) },
+ .driver_info = UVC_INFO_QUIRK(UVC_QUIRK_RESTORE_CTRLS_ON_INIT
+ | UVC_QUIRK_INVALID_DEVICE_SOF) },
/* Logitech HD Pro Webcam C922 */
{ .match_flags = USB_DEVICE_ID_MATCH_DEVICE
| USB_DEVICE_ID_MATCH_INT_INFO,
--
2.44.0