And regarding the magic number, it should be based on
dwMaxVideoFrameBufferSize, not on frame->wWidth , frame->wHeight (if
we decide to have a magic number).
or even better, we could have min_dwFrameInterval.
>
> >> + if (format->flags & UVC_FMT_FLAG_COMPRESSED) {
> >> + u32 bandwidth;
> >> +
> >> + if (!stream->dev->info->max_bandwidth || !frame->bFrameIntervalType)
> >> + return;
> >> +
> >> + for (i = 0; i < frame->bFrameIntervalType; ++i) {
> >> + bandwidth = frame->wWidth * frame->wHeight;
> >> + bandwidth *= UVC_FIVAL_DENOM / frame->dwFrameInterval[i];
> >
> > frame->dwFrameInterval[i] comes from the device, it is not sanitized.
> > We need to make sure it is not zero.
>
> That is a good point, in the non-compressed UVC_QUIRK_FIX_BANDWIDTH handling
> this is handled by doing:
>
> bandwidth *= UVC_FIVAL_DENOM / (frame->dwFrameInterval[i] + 1);
>
> I guess we should do the same here then ?
I prefer (max(1,frame->dwFrameInterval[i])
But you chose :)
>
> Regards,
>
> Hans
>
>
>
> >
> >> +
> >> + if (bandwidth <= stream->dev->info->max_bandwidth)
> >> + break;
> >> + }
> >> +
> >> + if (ctrl->dwFrameInterval < frame->dwFrameInterval[i])
> >> + ctrl->dwFrameInterval = frame->dwFrameInterval[i];
> >> +
> >> + return;
> >> + }
> >> +
> >> + if (stream->intf->num_altsetting > 1) {
> >> u32 interval;
> >> u32 bandwidth;
> >>
> >> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> >> index 966ff82c2ba8..6b702219173f 100644
> >> --- a/drivers/media/usb/uvc/uvcvideo.h
> >> +++ b/drivers/media/usb/uvc/uvcvideo.h
> >> @@ -535,6 +535,7 @@ static inline u32 uvc_urb_index(const struct uvc_urb *uvc_urb)
> >>
> >> struct uvc_device_info {
> >> u32 quirks;
> >> + u32 max_bandwidth; /* In pixels per second */
> >> u32 meta_format;
> >> u16 uvc_version;
> >> };
> >> --
> >> 2.47.1
> >>
> >>
> >
> >
>
--
Ricardo Ribalda
