Hi Ai, Thank you for the patch. On Tue, Nov 22, 2022 at 04:48:33PM +0800, Ai Chao wrote: > For Alcor Corp. Slave camera(1b17:6684/2017:0011), it support to output Could you please send me the USB descriptors for the 2017:0011 device (lsusb -v -d 2017:0011) ? > compressed video data, and it return a wrong dwMaxPayloadTransferSize > fields. This is a fireware issue, but the manufacturer cannot provide > a const return fieldsby the fireware. For some device, it requested > 2752512 B/frame bandwidth. For normally device, it requested 3072 or 1024 > B/frame bandwidth. so we check the dwMaxPayloadTransferSize fields,if it > large than 0x1000, reset dwMaxPayloadTransferSize to 1024, and the camera > preview normally. > > Signed-off-by: Ai Chao <aichao@xxxxxxxxxx> > > --- > change for v4 > - Change usb_match_one_id to usb_match_id > - Modify the discription > > change for v3 > - Add VID/PID 2017:0011 > > change for v2 > - Used usb_match_one_id to check VID and PID > --- > --- > drivers/media/usb/uvc/uvc_video.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index d2eb9066e4dc..75bdd71d0e5a 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -135,6 +135,11 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, > static const struct usb_device_id elgato_cam_link_4k = { > USB_DEVICE(0x0fd9, 0x0066) > }; > + static const struct usb_device_id alcor_corp_slave_cam[] = { > + { USB_DEVICE(0x2017, 0x0011) }, > + { USB_DEVICE(0x1b17, 0x6684) }, > + { } > + }; > struct uvc_format *format = NULL; > struct uvc_frame *frame = NULL; > unsigned int i; > @@ -234,6 +239,13 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, > > ctrl->dwMaxPayloadTransferSize = bandwidth; > } > + > + /* Alcor Corp. Slave camera return wrong dwMaxPayloadTransferSize */ > + if ((format->flags & UVC_FMT_FLAG_COMPRESSED) && Is the issue limited to MJPEG ? The device also supports YUYV, does it provide a correct dwMaxPayloadTransferSize in that case ? > + (ctrl->dwMaxPayloadTransferSize > 0x1000) && > + usb_match_id(stream->dev->intf, alcor_corp_slave_cam)) { > + ctrl->dwMaxPayloadTransferSize = 1024; > + } > } > > static size_t uvc_video_ctrl_size(struct uvc_streaming *stream) -- Regards, Laurent Pinchart