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);
>
> >
> >
> >>
> >> - 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
