diff options
Diffstat (limited to 'drivers/media/video/uvc/uvc_video.c')
| -rw-r--r-- | drivers/media/video/uvc/uvc_video.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c index 0789ba381fc..a95e17329c5 100644 --- a/drivers/media/video/uvc/uvc_video.c +++ b/drivers/media/video/uvc/uvc_video.c @@ -61,7 +61,7 @@ int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit, return 0; } -static void uvc_fixup_buffer_size(struct uvc_video_device *video, +static void uvc_fixup_video_ctrl(struct uvc_video_device *video, struct uvc_streaming_control *ctrl) { struct uvc_format *format; @@ -84,6 +84,31 @@ static void uvc_fixup_buffer_size(struct uvc_video_device *video, video->dev->uvc_version < 0x0110)) ctrl->dwMaxVideoFrameSize = frame->dwMaxVideoFrameBufferSize; + + if (video->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH && + video->streaming->intf->num_altsetting > 1) { + u32 interval; + u32 bandwidth; + + interval = (ctrl->dwFrameInterval > 100000) + ? ctrl->dwFrameInterval + : frame->dwFrameInterval[0]; + + /* 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). + */ + bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; + bandwidth *= 10000000 / interval + 1; + bandwidth /= 1000; + if (video->dev->udev->speed == USB_SPEED_HIGH) + bandwidth /= 8; + bandwidth += 12; + + ctrl->dwMaxPayloadTransferSize = bandwidth; + } } static int uvc_get_video_ctrl(struct uvc_video_device *video, @@ -158,10 +183,11 @@ static int uvc_get_video_ctrl(struct uvc_video_device *video, ctrl->bMaxVersion = 0; } - /* Some broken devices return a null or wrong dwMaxVideoFrameSize. - * Try to get the value from the format and frame descriptors. + /* Some broken devices return null or wrong dwMaxVideoFrameSize and + * dwMaxPayloadTransferSize fields. Try to get the value from the + * format and frame descriptors. */ - uvc_fixup_buffer_size(video, ctrl); + uvc_fixup_video_ctrl(video, ctrl); ret = 0; out: |