diff mbox series

[v10] media: uvcvideo: Fix bandwidth issue for Alcor camera.

Message ID 20250510061803.811433-1-ccc194101@163.com
State Superseded
Headers show
Series [v10] media: uvcvideo: Fix bandwidth issue for Alcor camera. | expand

Commit Message

chenchangcheng May 10, 2025, 6:18 a.m. UTC
From: chenchangcheng <chenchangcheng@kylinos.cn>

Some broken device return wrong dwMaxPayloadTransferSize fields
as follows:
    [  218.632537] [pid:20427,cpu6,guvcview,8]uvcvideo: Device requested 2752512 B/frame bandwidth.
    [  218.632598] [pid:20427,cpu6,guvcview,9]uvcvideo: No fast enough alt setting for requested bandwidth.

When dwMaxPayloadTransferSize is greater than maxpsize,
it will prevent the camera from starting.
So use the bandwidth of maxpsize.

Signed-off-by: chenchangcheng <chenchangcheng@kylinos.cn>
---
 drivers/media/usb/uvc/uvc_video.c | 9 +++++++++
 1 file changed, 9 insertions(+)


base-commit: d76bb1ebb5587f66b0f8b8099bfbb44722bc08b3

Comments

Ricardo Ribalda May 14, 2025, 9:17 a.m. UTC | #1
Hi chenchangcheng

Thanks for your patience fixing the warnings from media-ci :)

Regards

On Sat, 10 May 2025 at 08:18, chenchangcheng <ccc194101@163.com> wrote:
>
> From: chenchangcheng <chenchangcheng@kylinos.cn>
>
> Some broken device return wrong dwMaxPayloadTransferSize fields
> as follows:
>     [  218.632537] [pid:20427,cpu6,guvcview,8]uvcvideo: Device requested 2752512 B/frame bandwidth.
>     [  218.632598] [pid:20427,cpu6,guvcview,9]uvcvideo: No fast enough alt setting for requested bandwidth.
>
> When dwMaxPayloadTransferSize is greater than maxpsize,
> it will prevent the camera from starting.
> So use the bandwidth of maxpsize.
>
> Signed-off-by: chenchangcheng <chenchangcheng@kylinos.cn>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_video.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index e3567aeb0007..a74cf89852d1 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -262,6 +262,15 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
>
>                 ctrl->dwMaxPayloadTransferSize = bandwidth;
>         }
> +
> +       if (stream->intf->num_altsetting > 1 &&
> +           ctrl->dwMaxPayloadTransferSize > stream->maxpsize) {
> +               dev_warn_ratelimited(&stream->intf->dev,
> +                                    "the max payload transmission size (%d) exceededs the size of the ep max packet (%d). Using the max size.\n",
> +                                    ctrl->dwMaxPayloadTransferSize,

Minor nitpick. I am trying to standarize "UVC non compliance" header
in the logs for this kind of things.

"UVC non compliance: the max payload transmission size (%d) exceededs
the size of the ep max packet (%d). Using the max size.\n"
> +                                    stream->maxpsize);
> +               ctrl->dwMaxPayloadTransferSize = stream->maxpsize;
> +       }
>  }
>
>  static size_t uvc_video_ctrl_size(struct uvc_streaming *stream)
>
> base-commit: d76bb1ebb5587f66b0f8b8099bfbb44722bc08b3
> --
> 2.25.1
>
diff mbox series

Patch

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index e3567aeb0007..a74cf89852d1 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -262,6 +262,15 @@  static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
 
 		ctrl->dwMaxPayloadTransferSize = bandwidth;
 	}
+
+	if (stream->intf->num_altsetting > 1 &&
+	    ctrl->dwMaxPayloadTransferSize > stream->maxpsize) {
+		dev_warn_ratelimited(&stream->intf->dev,
+				     "the max payload transmission size (%d) exceededs the size of the ep max packet (%d). Using the max size.\n",
+				     ctrl->dwMaxPayloadTransferSize,
+				     stream->maxpsize);
+		ctrl->dwMaxPayloadTransferSize = stream->maxpsize;
+	}
 }
 
 static size_t uvc_video_ctrl_size(struct uvc_streaming *stream)