Messages in this thread | | | Date | Thu, 10 Jun 2021 20:14:02 +0300 | From | Laurent Pinchart <> | Subject | Re: [PATCH v9 20/22] uvcvideo: improve error handling in uvc_query_ctrl() |
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Hi Ricardo and Hans,
Thank you for the patch.
On Fri, Mar 26, 2021 at 10:58:38AM +0100, Ricardo Ribalda wrote: > From: Hans Verkuil <hverkuil-cisco@xs4all.nl> > > - 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.
I would have split the commit in two.
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> > --- > > I have changed a bit the patch from the original version. > > drivers/media/usb/uvc/uvc_video.c | 38 +++++++++++++++++-------------- > 1 file changed, 21 insertions(+), 17 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index b63c073ec30e..1c3a94d91724 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -76,35 +76,31 @@ 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); > - > - if (ret != -EPIPE) > - return ret; > + if (ret < 0 && ret != -EPIPE) > + goto err; > > + // reuse data[0] for request the error code.
C-style comments please.
s/for request/to request/
> 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); > -
No need to drop the blank lines.
> error = *(u8 *)data; > *(u8 *)data = tmp; > > - if (ret != 1) > - return ret < 0 ? ret : -EPIPE; > + if (ret != 1) { > + ret = ret < 0 ? ret : -EPIPE; > + goto err; > + } > > - uvc_dbg(dev, CONTROL, "Control error %u\n", error); > + dev_dbg(&dev->udev->dev,
Why not uvc_dbg ?
> + "Failed to query (%s) UVC control %u on unit %u: got error %u.\n", > + uvc_query_name(query), cs, unit, error); > > 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 */ > @@ -120,10 +116,18 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, > case 8: /* Invalid value within range */ > return -EINVAL; > default: /* reserved or unknown */ > - break; > + dev_err(&dev->udev->dev, > + "Failed to query (%s) UVC control %u on unit %u: got error %u.\n", > + uvc_query_name(query), cs, unit, error);
when debugging is enabled, this will print the error message a second time, it's not very nice.
> + return -EPIPE; > } > > - return -EPIPE; > +err: > + 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; > } > > static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
-- Regards,
Laurent Pinchart
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