Re: [PATCH v3 4/9] media: venus: vdec: add video decoder files

[Stanimir Varbanov]

Hi Hans,

Thanks for the comments!

On 11/11/2016 01:39 PM, Hans Verkuil wrote:
> I made some comments about start_streaming in my review of patch 3/9, so
> I am not going to repeat that here.

Sure.

> 
> On 11/07/2016 06:33 PM, Stanimir Varbanov wrote:
>> This consists of video decoder implementation plus decoder
>> controls.
>>
>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
>> ---
>>  drivers/media/platform/qcom/venus/vdec.c       | 1108 ++++++++++++++++++++++++
>>  drivers/media/platform/qcom/venus/vdec.h       |   32 +
>>  drivers/media/platform/qcom/venus/vdec_ctrls.c |  197 +++++
>>  3 files changed, 1337 insertions(+)
>>  create mode 100644 drivers/media/platform/qcom/venus/vdec.c
>>  create mode 100644 drivers/media/platform/qcom/venus/vdec.h
>>  create mode 100644 drivers/media/platform/qcom/venus/vdec_ctrls.c
>>
>> diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c
>> new file mode 100644
>> index 000000000000..3f0eba7e31dc
>> --- /dev/null
>> +++ b/drivers/media/platform/qcom/venus/vdec.c
> 
> <snip>
> 
>> +static int
>> +vdec_s_selection(struct file *file, void *fh, struct v4l2_selection *s)
>> +{
>> +	struct venus_inst *inst = to_inst(file);
>> +
>> +	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
>> +	    s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
>> +		return -EINVAL;
>> +
>> +	switch (s->target) {
>> +	case V4L2_SEL_TGT_CROP_BOUNDS:
>> +	case V4L2_SEL_TGT_CROP_DEFAULT:
>> +	case V4L2_SEL_TGT_CROP:
>> +		return -EINVAL;
>> +	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
>> +	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
>> +	case V4L2_SEL_TGT_COMPOSE_PADDED:
>> +		return -EINVAL;
>> +	case V4L2_SEL_TGT_COMPOSE:
>> +		if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>> +			return -EINVAL;
>> +		s->r.width = inst->out_width;
>> +		s->r.height = inst->out_height;
>> +		break;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	s->r.top = 0;
>> +	s->r.left = 0;
>> +
>> +	return 0;
>> +}
> 
> This can be simplified to just:
> 
> 	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
> 	    s->target != V4L2_SEL_TGT_COMPOSE)
> 		return -EINVAL;
> 
> 	// handle the remaining capture compose case

OK I will rewrite it.

> 
>> +
>> +static int
>> +vdec_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *b)
>> +{
>> +	struct vb2_queue *queue = to_vb2q(file, b->type);
>> +
>> +	if (!queue)
>> +		return -EINVAL;
>> +
>> +	return vb2_reqbufs(queue, b);
>> +}
> 
> Is there any reason why the v4l2_m2m_ioctl_reqbufs et al helper functions
> can't be used? I strongly recommend that, unless there is a specific reason
> why that won't work.

So that means I need to completely rewrite the v4l2 part and adopt it
for mem2mem device APIs.

If that is what you meant I can invest some time to make a estimation
what would be the changes and time needed. After that we can decide what
to do - take the driver as is and port it to mem2mem device APIs later
on or wait for the this transition to happen before merging.

-- 
regards,
Stan