Re: Support for 2D engines/blitters in V4L2 and DRM
From: Tomasz Figa
Date: Thu Apr 18 2019 - 05:22:10 EST
On Thu, Apr 18, 2019 at 6:14 PM Paul Kocialkowski
> On Thu, 2019-04-18 at 18:09 +0900, Tomasz Figa wrote:
> > On Thu, Apr 18, 2019 at 5:55 PM Paul Kocialkowski
> > <paul.kocialkowski@xxxxxxxxxxx> wrote:
> > > Hi Daniel,
> > >
> > > On Thu, 2019-04-18 at 10:18 +0200, Daniel Vetter wrote:
> > > > On Wed, Apr 17, 2019 at 08:10:15PM +0200, Paul Kocialkowski wrote:
> > > > > Hi Nicolas,
> > > > >
> > > > > I'm detaching this thread from our V4L2 stateless decoding spec since
> > > > > it has drifted off and would certainly be interesting to DRM folks as
> > > > > well!
> > > > >
> > > > > For context: I was initially talking about writing up support for the
> > > > > Allwinner 2D engine as a DRM render driver, where I'd like to be able
> > > > > to batch jobs that affect the same destination buffer to only signal
> > > > > the out fence once when the batch is done. We have a similar issue in
> > > > > v4l2 where we'd like the destination buffer for a set of requests (each
> > > > > covering one H264 slice) to be marked as done once the set was decoded.
> > > > >
> > Out of curiosity, what area did you find a 2D blitter useful for?
> The initial motivation is to bring up a DDX with that for platforms
> that have 2D engines but no free software GPU drivers yet.
> I also have a personal project in the works where I'd like to implement
> accelerated UI rendering in 2D. The idea is to avoid using GL entirely.
> That last point is in part because I have a GPU-less device that I want
> to get going with mainline: http://linux-sunxi.org/F60_Action_Camera
I feel like the typical DRM model with a render node and a userspace
library would make sense for these specific use cases on these
specific hardware platforms then.
Hopefully the availability of open drivers for 3D engines continues to improve.