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.
>
>
>>
>> - 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
