Hi Ricardo,
On Tue, Oct 08, 2024 at 07:06:14AM +0000, Ricardo Ribalda wrote:
Some cameras, like the ELMO MX-P3, do not return all the bytes requested from a control if it can fit in less bytes. Eg: Returning 0xab instead of 0x00ab. usb 3-9: Failed to query (GET_DEF) UVC control 3 on unit 2: 1 (exp. 2).
Extend the returned value from the camera and return it.
Cc: stable@vger.kernel.org Fixes: a763b9fb58be ("media: uvcvideo: Do not return positive errors in uvc_query_ctrl()")
Is this really the patch that introduced the problem?
Signed-off-by: Ricardo Ribalda ribalda@chromium.org
drivers/media/usb/uvc/uvc_video.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index cd9c29532fb0..853dfb7b5f7b 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -79,11 +79,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, if (likely(ret == size)) return 0;
- if (ret > 0 && ret < size) {
memset(data + ret, 0, size - ret);
It'd be nice to have a comment in the code why this is being done (including it's little endian).
return 0;- }
- if (ret != -EPIPE) { dev_err(&dev->udev->dev, "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", uvc_query_name(query), cs, unit, ret, size);
return ret < 0 ? ret : -EPIPE;
return ret ? ret : -EPIPE;/* Reuse data[0] to request the error code. */