Re: [PATCH 1/6] V4L2: Add Renesas R-Car JPEG codec driver.

Hans Verkuil
2014-08-22T17:04:30Z

On 08/22/2014 01:39 PM, Mikhail Ulianov wrote:
> Hi Hans,
>
> Thanks for your comments.
>
> I have a question on default width, height and sizeimage values
> m2m driver should return in case when we try to run G_FMT on just
> opened device. Is there any preferable values? v4l2-compliance tool
> want it to be non zero, but at that moment we have no information
> about output and capture, so i see few options here:
> 1) ignore v4l-complince error in such case
>>> v4l2-test-formats.cpp(417): !pix.width || !pix.height"
> 2) set some default values e.g. 640x480
> Do you have a suggestion? \

Use 2: just set a default value. V4L2 should always be in a sane state,
which in this case means that the driver should just pick some default
initial format.

Regards,

Hans

>
> Thanks, Mikhail.
>
>> Hi Mikhail,
>>
>> I did a quick scan over the source code and I noticed a few things
>> that aren't right. The easiest for you is probably to run the
>> v4l2-compliance tool over your driver and it should tell you what
>> needs to be fixed. The things I noticed are: querycap doesn't fill in
>> bus_info (should be 'platform:<foo>') and device_caps, the vid_cap
>> try_fmt fails on a wrong field setting, instead it should just set it.
>>
>> I also have some doubts about g_selection, but I need to look at that
>> again when I have more time next week. It does look like it is not
>> properly separating the capture and output streams. I would expect
>> g_selection to return different things for capture and output. Note
>> that v4l2-compliance doesn't yet check the selection API, so it won't
>> help you there.
>>
>> Regards,
>>
>> Hans