Re: [RFCv2 PATCH 7/9] vb2: add thread support

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

On Tuesday 03 December 2013 10:56:07 Hans Verkuil wrote:
> On 11/29/13 19:21, Laurent Pinchart wrote:
> > On Friday 29 November 2013 10:58:42 Hans Verkuil wrote:
> >> From: Hans Verkuil <hans.verkuil@cisco.com>
> >> 
> >> In order to implement vb2 DVB or ALSA support you need to be able to
> >> start a kernel thread that queues and dequeues buffers, calling a
> >> callback function for every captured/displayed buffer. This patch adds
> >> support for that.
> >> 
> >> It's based on drivers/media/v4l2-core/videobuf-dvb.c, but with all the
> >> DVB specific stuff stripped out, thus making it much more generic.
> > 
> > Do you see any use for this outside of videobuf2-dvb ? If not I wonder
> > whether the code shouldn't be moved there. The sync objects framework
> > being developed for KMS will in my opinion cover the other use cases, and
> > I'd like to discourage non-DVB drivers to use vb2 threads in the
> > meantime.
> 
> I'm using it for ALSA drivers which, at least in my case, require almost
> identical functionality as that needed by DVB.

You're using videobuf2 for audio ?

> But regardless of that, I really don't like the way it was done in the old
> videobuf framework, mixing low-level videobuf calls/data structure accesses
> with DVB code. That should be separate.
> 
> The vb2 core framework should provide the low-level functionality that is
> needed by the videobuf2-dvb to build on.

Right, but I want to make sure that drivers will not start using this 
directly. It should be an internal videobuf2 API.

-- 
Regards,

Laurent Pinchart