From: Laurent Pinchart Date: Tue, 12 May 2015 21:57:53 +0000 (-0300) Subject: [media] uvcvideo: Fix incorrect bandwidth with Chicony device 04f2:b50b X-Git-Tag: firefly_0821_release~176^2~795^2~610 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=37f85b276a36b531234992b05eb057841af46fb4;p=firefly-linux-kernel-4.4.55.git [media] uvcvideo: Fix incorrect bandwidth with Chicony device 04f2:b50b The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to compute the bandwidth on 16 bits and erroneously sign-extend it to 32 bits, resulting in a huge bandwidth value. Detect and fix that condition by setting the 16 MSBs to 0 when they're all equal to 1. Reported-by: Hans de Goede Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 20ccc9d315dc..f839654ea436 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -119,6 +119,14 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, ctrl->dwMaxVideoFrameSize = frame->dwMaxVideoFrameBufferSize; + /* The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to + * compute the bandwidth on 16 bits and erroneously sign-extend it to + * 32 bits, resulting in a huge bandwidth value. Detect and fix that + * condition by setting the 16 MSBs to 0 when they're all equal to 1. + */ + if ((ctrl->dwMaxPayloadTransferSize & 0xffff0000) == 0xffff0000) + ctrl->dwMaxPayloadTransferSize &= ~0xffff0000; + if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) && stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH && stream->intf->num_altsetting > 1) {