Re: [PATCH v6 0/8] drm: Support per-plane async flip configuration

[André Almeida]

Hi Dmitry,

Em 14/06/2024 14:32, Dmitry Baryshkov escreveu:
> On Fri, Jun 14, 2024 at 12:35:27PM GMT, André Almeida wrote:
> > AMD hardware can do async flips with overlay planes, but currently there's no
> > easy way to enable that in DRM. To solve that, this patchset creates a new
> > drm_plane field, bool async_flip, that allows drivers to choose which plane can
> > or cannot do async flips. This is latter used on drm_atomic_set_property when
> > users want to do async flips.
> >
> > Patch 1 allows async commits with IN_FENCE_ID in any driver.
> >
> > Patches 2 to 7 have no function change. As per current code, every driver that
> > allows async page flips using the atomic API, allows doing it only in the
> > primary plane. Those patches then enable it for every driver.
> >
> > Patch 8 finally enables async flip on overlay planes for amdgpu.
> >
> > Changes from v5:
> > - Instead of enabling plane->async_flip in the common code, move it to driver
> > code.
> > - Enable primary plane async flip on every driver
> > https://lore.kernel.org/dri-devel/20240612193713.167448-1-andrealmeid@xxxxxxxxxx/
> >
> > André Almeida (8):
> >    drm/atomic: Allow userspace to use explicit sync with atomic async
> >      flips
> >    drm: Support per-plane async flip configuration
> >    drm/amdgpu: Enable async flips on the primary plane
> >    drm: atmel-hlcdc: Enable async flips on the primary plane
> >    drm/i915: Enable async flips on the primary plane
> >    drm/nouveau: Enable async flips on the primary plane
> >    drm/vc4: Enable async flips on the primary plane
> >    drm/amdgpu: Make it possible to async flip overlay planes
> >
> >   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 2 ++
> >   drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c         | 3 +++
> >   drivers/gpu/drm/drm_atomic_uapi.c                       | 8 +++++---
> >   drivers/gpu/drm/i915/display/i9xx_plane.c               | 3 +++
> >   drivers/gpu/drm/nouveau/dispnv04/crtc.c                 | 4 ++++
> >   drivers/gpu/drm/nouveau/dispnv50/wndw.c                 | 4 ++++
> >   drivers/gpu/drm/vc4/vc4_plane.c                         | 4 +++-
>
> The main question is why only these drivers were updated.

According to `git grep async_page_flip`, only those drivers supports 
async page flip. The only corner case is radeon, that does supports 
async but doesn't support planes.

Do you know any other driver that should be updated to?

> >   include/drm/drm_plane.h                                 | 5 +++++
> >   8 files changed, 29 insertions(+), 4 deletions(-)
> >
> > --
> > 2.45.2