Re: [PATCH] media: usb: uvc: fill in description for unknown pixelformats

["Linux regression tracking (Thorsten Leemhuis)" <regressions@leemhuis.info>]

On 31.05.23 14:44, Laurent Pinchart wrote:
> Hi Thorsten,
> 
> On Wed, May 31, 2023 at 01:48:51PM +0200, Linux regression tracking (Thorsten Leemhuis) wrote:
>> On 29.03.23 14:28, Hans Verkuil wrote:
>>> If the fcc is 0 (indicating an unknown GUID format), then fill in the
>>> description field in ENUM_FMT. Otherwise the V4L2 core will WARN.
>>
>> What happened to this? It seems this fall through the cracks.
> 
> I've posted a better fix,

You mean an even better fix, as this one already was a better fix for a
earlier fix ;)

> see
> https://lore.kernel.org/linux-media/20230506065809.24645-1-laurent.pinchart@ideasonboard.com/.
> Of course, fate had it that it got reviewed exactly on the day when I started by holidays :-S

:-D

> I'm now back, and will send a pull request.

In that case: welcome back.

>> BTW:
>>
>>> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
>>
>> Afaics it might be good to have these in here:
>>
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=217252
>> Link: https://bugzilla.redhat.com/show_bug.cgi?id=2180107
> 
> I'll add those two links.

Great, many thx!

Ciao, Thorsten

>> A comment in the former is what brought me here.
>>
>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
>> --
>> Everything you wanna know about Linux kernel regression tracking:
>> https://linux-regtracking.leemhuis.info/about/#tldr
>> If I did something stupid, please tell me, as explained on that page.
>>
>> #regzbot ^backmonitor:
>> https://lore.kernel.org/lkml/dc8e5276-ef88-648f-9f0d-10151ea62c90@leemhuis.info/
>> #regzbot poke
>>
>>> Fixes: 50459f103edf ("media: uvcvideo: Remove format descriptions")
>>> ---
>>> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
>>> index 7aefa76a42b3..2f1ced1212cd 100644
>>> --- a/drivers/media/usb/uvc/uvc_driver.c
>>> +++ b/drivers/media/usb/uvc/uvc_driver.c
>>> @@ -256,6 +256,9 @@ static int uvc_parse_format(struct uvc_device *dev,
>>>  		} else {
>>>  			dev_info(&streaming->intf->dev,
>>>  				 "Unknown video format %pUl\n", &buffer[5]);
>>> +			snprintf(format->name, sizeof(format->name), "%pUl\n",
>>> +				 &buffer[5]);
>>> +
>>>  			format->fcc = 0;
>>>  		}
>>>
>>> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
>>> index 35453f81c1d9..fc6f9e7d8506 100644
>>> --- a/drivers/media/usb/uvc/uvc_v4l2.c
>>> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
>>> @@ -713,6 +713,10 @@ static int uvc_ioctl_enum_fmt(struct uvc_streaming *stream,
>>>  	if (format->flags & UVC_FMT_FLAG_COMPRESSED)
>>>  		fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
>>>  	fmt->pixelformat = format->fcc;
>>> +	if (format->name[0])
>>> +		strscpy(fmt->description, format->name,
>>> +			sizeof(fmt->description));
>>> +
>>>  	return 0;
>>>  }
>>>
>>> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
>>> index 9a596c8d894a..22656755a801 100644
>>> --- a/drivers/media/usb/uvc/uvcvideo.h
>>> +++ b/drivers/media/usb/uvc/uvcvideo.h
>>> @@ -264,6 +264,8 @@ struct uvc_format {
>>>  	u32 fcc;
>>>  	u32 flags;
>>>
>>> +	char name[32];
>>> +
>>>  	unsigned int nframes;
>>>  	struct uvc_frame *frame;
>>>  };
>