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 :-)
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
>
>
>
