Re: [PATCH RESEND v5 2/5] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922

From: Sergey Senozhatsky
Date: Thu Mar 09 2023 - 00:31:21 EST


On (23/03/08 23:45), Ricardo Ribalda wrote:
[..]
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -541,7 +541,13 @@ 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);

What host_sof is set to? Some stack garbage?

> + /*
> + * 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 = usb_get_current_frame_number(stream->dev->udev);
> +
> time = uvc_video_get_time();