Hi Hans
Thanks for the patch. I like how uvc is ending :)
On Mon, Mar 22, 2021 at 1:09 PM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
>
> - If __uvc_query_ctrl() failed with a non-EPIPE error, then
> report that with dev_err. If an error code is obtained, then
> report that with dev_dbg.
>
> - For error 2 (Wrong state) return -EACCES instead of -EILSEQ.
> EACCES is a much more appropriate error code. EILSEQ will return
> "Invalid or incomplete multibyte or wide character." in strerror(),
> which is a *very* confusing message.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> Ricardo, this too can be added to the uvc series.
> ---
> drivers/media/usb/uvc/uvc_video.c | 44 +++++++++++++++++--------------
> 1 file changed, 24 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index b63c073ec30e..3f461bb4eeb9 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -68,7 +68,7 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
> u8 intfnum, u8 cs, void *data, u16 size)
> {
> int ret;
> - u8 error;
> + u8 error = 0;
> u8 tmp;
>
> ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
> @@ -76,35 +76,39 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
> if (likely(ret == size))
> return 0;
>
> - dev_dbg(&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);
> + ret = ret < 0 ? ret : -EPIPE;
>
> - if (ret != -EPIPE)
> - return ret;
> -
> - tmp = *(u8 *)data;
> + if (ret == -EPIPE) {
> + tmp = *(u8 *)data;
>
> - ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum,
> - UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1,
> - UVC_CTRL_CONTROL_TIMEOUT);
> + ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum,
> + UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1,
> + UVC_CTRL_CONTROL_TIMEOUT);
>
> - error = *(u8 *)data;
> - *(u8 *)data = tmp;
> + if (ret == 1)
> + error = *(u8 *)data;
> + *(u8 *)data = tmp;
> + if (ret != 1)
> + ret = ret < 0 ? ret : -EPIPE;
> + }
>
> - if (ret != 1)
> - return ret < 0 ? ret : -EPIPE;
> + if (error)
> + dev_dbg(&dev->udev->dev,
> + "Failed to query (%s) UVC control %u on unit %u: got error %u.\n",
> + uvc_query_name(query), cs, unit, error);
> + else
> + 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);
If __uvc_query_ctrl and UVC_VC_REQUEST_ERROR_CODE_CONTROL failed,
error is 0. And I think that you want to show a dev_err in that case.
Maybe we can initialize error to 7 ?
>
> - uvc_dbg(dev, CONTROL, "Control error %u\n", error);
> + if (!error)
> + return ret;
I think we do not want these two lines (read next comment)
>
> switch (error) {
> - case 0:
> - /* Cannot happen - we received a STALL */
> - return -EPIPE;
> case 1: /* Not ready */
> return -EBUSY;
> case 2: /* Wrong state */
> - return -EILSEQ;
> + return -EACCES;
> case 3: /* Power */
> return -EREMOTE;
> case 4: /* Out of range */
Maybe we want a dev_dbg if the error code is unknown and return ret?
> --
> 2.30.0
>
--
Ricardo Ribalda
