| Message ID | 20240414190040.2255a0bc@foxbook (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | media: uvcvideo: fix the bandwdith quirk on USB 3.x | expand |
Hi Michal On Sun, 14 Apr 2024 at 19:00, Michal Pecio <michal.pecio@gmail.com> wrote: > > The bandwidth fixup quirk doesn't know that SuperSpeed exists and has > the same 8 service intervals per millisecond as High Speed, hence its > calculations are wrong. > > Assume that all speeds from HS up use 8 intervals per millisecond. > > No further changes are needed, updated code has been confirmed to work > with all speeds from FS to SS. > > Signed-off-by: Michal Pecio <michal.pecio@gmail.com> Reviewed-by: Ricardo Ribalda <ribalda@chromium.org> > --- > drivers/media/usb/uvc/uvc_video.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index 28dde08ec6c5..4b86bef06a52 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -214,13 +214,13 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, > * Compute a bandwidth estimation by multiplying the frame > * size by the number of video frames per second, divide the > * result by the number of USB frames (or micro-frames for > - * high-speed devices) per second and add the UVC header size > - * (assumed to be 12 bytes long). > + * high- and super-speed devices) per second and add the UVC > + * header size (assumed to be 12 bytes long). > */ > bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; > bandwidth *= 10000000 / interval + 1; > bandwidth /= 1000; > - if (stream->dev->udev->speed == USB_SPEED_HIGH) > + if (stream->dev->udev->speed >= USB_SPEED_HIGH) > bandwidth /= 8; > bandwidth += 12; > > -- > 2.43.0 > >
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 28dde08ec6c5..4b86bef06a52 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -214,13 +214,13 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, * Compute a bandwidth estimation by multiplying the frame * size by the number of video frames per second, divide the * result by the number of USB frames (or micro-frames for - * high-speed devices) per second and add the UVC header size - * (assumed to be 12 bytes long). + * high- and super-speed devices) per second and add the UVC + * header size (assumed to be 12 bytes long). */ bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; bandwidth *= 10000000 / interval + 1; bandwidth /= 1000; - if (stream->dev->udev->speed == USB_SPEED_HIGH) + if (stream->dev->udev->speed >= USB_SPEED_HIGH) bandwidth /= 8; bandwidth += 12;
The bandwidth fixup quirk doesn't know that SuperSpeed exists and has the same 8 service intervals per millisecond as High Speed, hence its calculations are wrong. Assume that all speeds from HS up use 8 intervals per millisecond. No further changes are needed, updated code has been confirmed to work with all speeds from FS to SS. Signed-off-by: Michal Pecio <michal.pecio@gmail.com> --- drivers/media/usb/uvc/uvc_video.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)