[v3,4/8] media: uvcvideo: Do not return positive errors in uvc_query_ctrl()

Message ID 20220920-resend-v4l2-compliance-v3-4-598d33a15815@chromium.org
State New
Headers
Series Follow-up patches for uvc v4l2-compliance |

Commit Message

Ricardo Ribalda Jan. 3, 2023, 2:36 p.m. UTC
  If the returned size of the query does not match the expected size or it
is zero, return -EPIPE instead of 0 or a positive value.

This will avoid confusing the caller (and ultimately userspace) that
doesn't expect a positive or zero value.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_video.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Patch

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index e56ccde9bd10..feba058fcb06 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -83,7 +83,7 @@  int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
 		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;
+		return ret < 0 ? ret : -EPIPE;
 	}
 
 	/* Reuse data[0] to request the error code. */