If we fail to query the ctrl error code there is no information on dmesg
or in uvc_dbg. This makes difficult to debug the issue.
Print a proper error message when we cannot retrieve the error code from
the device.
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_video.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index e165850397a0..0195394e10b5 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -110,8 +110,12 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
error = *(u8 *)data;
*(u8 *)data = tmp;
- if (ret != 1)
+ if (ret != 1) {
+ dev_err_ratelimited(&dev->udev->dev,
+ "Failed to query (%s) UVC error code control %u on unit %u: %d (exp. 1).\n",
+ uvc_query_name(query), cs, unit, ret);
return ret < 0 ? ret : -EPIPE;
+ }
uvc_dbg(dev, CONTROL, "Control error %u\n", error);
--
2.47.0.338.g60cca15819-goog
