[Mesa-dev] [PATCH v5 4/5] st/dri2: Implement DRI2bufferDamageExtension
Boris Brezillon
boris.brezillon at collabora.com
Mon Jul 15 07:23:43 UTC 2019
Hello Marek,
On Tue, 2 Jul 2019 20:09:23 +0200
Boris Brezillon <boris.brezillon at collabora.com> wrote:
> On Tue, 2 Jul 2019 13:21:31 -0400
> Marek Olšák <maraeo at gmail.com> wrote:
>
> > On Tue., Jul. 2, 2019, 09:50 Boris Brezillon,
> > <boris.brezillon at collabora.com> wrote:
> >
> > > From: Daniel Stone <daniels at collabora.com>
> > >
> > > Add a pipe_screen->set_damage_region() hook to propagate
> > > set-damage-region requests to the driver, it's then up to the
> > > driver to decide what to do with this piece of information.
> > >
> > > If the hook is left unassigned, the buffer-damage extension is
> > > considered unsupported.
> > >
> > > Signed-off-by: Daniel Stone <daniels at collabora.com>
> > > Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> > > Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
> > > ---
> > > Changes in v5:
> > > * Add Alyssa's R-b
> > > ---
> > > src/gallium/include/pipe/p_screen.h | 7 +++++++
> > > src/gallium/state_trackers/dri/dri2.c | 22 ++++++++++++++++++++++
> > > 2 files changed, 29 insertions(+)
> > >
> > > diff --git a/src/gallium/include/pipe/p_screen.h
> > > b/src/gallium/include/pipe/p_screen.h
> > > index 3f9bad470950..8df12ee4f865 100644
> > > --- a/src/gallium/include/pipe/p_screen.h
> > > +++ b/src/gallium/include/pipe/p_screen.h
> > > @@ -464,6 +464,13 @@ struct pipe_screen {
> > > bool (*is_parallel_shader_compilation_finished)(struct
> > > pipe_screen *screen,
> > > void *shader,
> > > unsigned
> > > shader_type); +
> > > + /**
> > > + * Set damage region.
> > >
> >
> > Can you expand the comment to describe rects? The format of rects is
> > not obvious.
>
> Oops, will point to the KHR_partial_update() doc and explain what rects
> encode and how.
> This reminds me that we have a corner case (at least for tile-based
> GPUs): the dri implementation calls
> ->set_damage_region(screen, res, 0, NULL) to reset the damage region,
> but in KHR_partial_update() spec this means "damage all". If we follow
> the spec that would imply existing FB content is dropped which in turn
> means users relying on buffer_age() (without partial_update()) to only
> update the region that have changed will stop working properly.
>
> I see 2 options to solve this problem:
>
> 1/ add a new ->reset_damage_region() hook that would be called by the
> dri implementation after each swap_buf() in replacement of the
> current ->set_damage_region(screen, res, 0, NULL). Reset in that
> case means we consider the damage region as "unknown" and force
> a "reload FB content in the local-tile buffer" for the whole
> resource instead of restricting it to the !damage region.
> 2/ deviate from the KHR_partial_update() semantic and reserve
> ->set_damage_region(screen, res, 0, NULL) for the "reset damage
> region" op. That means we'll have to convert actual
> KHR_partial_update(0, NULL) calls into
> ->set_damage_region(screen, res, 1, full_res_rect) ones to reflect
> the behavior described in the spec.
Any advice on how to solve this problem?
Regards,
Boris
More information about the mesa-dev
mailing list