Hi Paul,
Thank you for the patch.
On Tuesday, 24 April 2018 23:59:36 EEST Paul Elder wrote:
> Down the call stack from the ioctl handler for VIDIOC_STREAMON,
> uvc_video_alloc_requests contains a BUG_ON, which in the high level,
> triggers when VIDIOC_STREAMON ioctl is issued without VIDIOC_STREAMOFF
> being issued previously.
>
> This can also be triggered by starting the stream and then physically
> disconnecting usb. To fix this, do the streamoff procedures on usb
> disconnect.
>
> Signed-off-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
> ---
> Changes in v2: Nothing
>
> drivers/usb/gadget/function/f_uvc.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/f_uvc.c
> b/drivers/usb/gadget/function/f_uvc.c index fa34dcbe1197..5bb79888e3f7
> 100644
> --- a/drivers/usb/gadget/function/f_uvc.c
> +++ b/drivers/usb/gadget/function/f_uvc.c
> @@ -374,9 +374,12 @@ uvc_function_disable(struct usb_function *f)
> {
> struct uvc_device *uvc = to_uvc(f);
> struct v4l2_event v4l2_event;
> + struct uvc_video *video = &uvc->video;
>
> INFO(f->config->cdev, "uvc_function_disable\n");
>
> + uvcg_video_enable(video, 0);
> +
As commented in my reply to patch 2/3, you will need to protect this with
proper locking. You now have at least four events dealing with states and
buffers allocation (VIDIOC_STREAMON, VIDIOC_STREAMOFF, uvc_function_set_alt
and uvc_function_disable).
> memset(&v4l2_event, 0, sizeof(v4l2_event));
> v4l2_event.type = UVC_EVENT_DISCONNECT;
> v4l2_event_queue(&uvc->vdev, &v4l2_event);
--
Regards,
Laurent Pinchart
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