Re: [RFC] [Patch] implement video driver for sur40

[Hans Verkuil <hverkuil@xs4all.nl>]

On 01/06/2015 01:09 PM, Florian Echtler wrote:
> On 06.01.2015 11:23, Hans Verkuil wrote:
>> On 01/06/2015 11:17 AM, Florian Echtler wrote:
>>>> You're not filling in the 'field' field of struct v4l2_buffer when returning a
>>>> frame. It should most likely be FIELD_NONE in your case.
>>>>>  		fail: v4l2-test-buffers.cpp(611): buf.check(q, last_seq)
>>>>>  		fail: v4l2-test-buffers.cpp(884): captureBufs(node, q, m2m_q, frame_count, false)
>>> OK, easy to fix. This will also influence the other two warnings, I assume?
>> Most likely, yes.
> Done. I would say that it's nearly ready for submission now (all tests
> from v4l2-compliance -s pass), I still have to sort out all the warnings
> from scripts/checkpatch.pl.
> 
>>>>> On a different note, I'm getting occasional warnings in syslog when I run 
>>>>> a regular video streaming application (e.g. cheese):
>>> Is there another possible explanation?
>> No :-)
>> You are still missing a buffer somewhere. I'd have to see your latest source code
>> to see what's wrong.
> Weirdly enough, the syslog warning/error doesn't seem to occur anymore
> since I've fixed the v4l2_buffer field. Perhaps some oddity within cheese?
> 
> I'm attaching the current source again for you to maybe have another
> look; I will submit a proper patch in the next days.

Just a few quick remarks:

- run scripts/checkpatch.pl over your source, I'm fairly certain it will complain
  about several constructs.
- use videobuf2-vmalloc instead of dma-contig. There is no DMA involved, so there
  is no reason to use dma-contig.
- Don't set V4L2_CAP_EXT_PIX_FORMAT in querycap: it will be set automatically by
  the v4l2 core.

Regards,

	Hans