Hi Hans
On Thu, Mar 25, 2021 at 2:57 PM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
>
> On 25/03/2021 14:54, Ricardo Ribalda wrote:
> > hi Hans
> >
> > On Thu, Mar 25, 2021 at 1:18 PM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
> >>
> >> On 23/03/2021 16:25, Ricardo Ribalda Delgado wrote:
> >>> 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 ?
> >>
> >> I'm confused, if error == 0, then it does show dev_err.
> >
> > My bad.
> >
> > Ignore the message.
> >
> > Can we write it as ?:
> >
> > 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);
> > return ret;
> > }
> >
> > 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);
>
> Sure! Just take this patch as inspiration :-)
Do you mind if I modify it before resend?
>
> Regards,
>
> Hans
>
> >
> >
> >
> >>
> >>>
> >>>
> >>>>
> >>>> - 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?
> >>
> >> Make sense.
> >>
> >> Regards,
> >>
> >> Hans
> >
> >
> >
>
--
Ricardo Ribalda
