Re: [PATCH v6 0/3] Expose modifiers/formats supported by async flips

[Simona Vetter <simona.vetter@ffwll.ch>]

On Wed, Feb 19, 2025 at 02:47:22PM +0530, Arun R Murthy wrote:
> All of the formats/modifiers supported by the plane during synchronous
> flips are nor supported by asynchronous flips. The formats/modifiers
> exposed to user by IN_FORMATS exposes all formats/modifiers supported by
> plane and this list varies for async flips. If the async flip supported
> formats/modifiers are exposed to the user, user based on this list can
> take decision to proceed or not and avoid flip failures during async
> flips.
> Discussion around this can be located @
> https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29618#note_2487123
> Userspace implementation for IN_FORMARTS_ASYNC under review @
> https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4063
> 
> TODO: Upon merge of the patch related to async flip
> https://patchwork.freedesktop.org/patch/626849/?series=139807&rev=6
> the patch 5 in this series will have to make use of the new function
> pointer can_async_flip().
> 
> v3: Add new plane->funcs format_mod_supported_async (Ville)
> 
> Arun R Murthy (3):
>   drm/plane: Add new plane property IN_FORMATS_ASYNC
>   drm/plane: Expose function to create format/modifier blob
>   drm/i915/display: Populate list of async supported formats/modifiers

Somewhat orthogonal, but in a different atomic kms discussion the much
bigger question of what are compositors supposed to figure out with
TEST_ONLY and what are they supposed to figure out through special
properties cropped up. Might be really good to document that, so that we
can have some design consistency here.

I think this patch series should also document why we need this and
compositors can't figure this out on their own, ideally by linking/quoting
the relevant discussions in the compositor enabling PR.

Thanks, Sima

> 
>  drivers/gpu/drm/drm_mode_config.c             |  7 +++
>  drivers/gpu/drm/drm_plane.c                   | 50 ++++++++++++------
>  .../drm/i915/display/skl_universal_plane.c    | 51 +++++++++++++++++++
>  include/drm/drm_mode_config.h                 |  6 +++
>  include/drm/drm_plane.h                       |  4 ++
>  5 files changed, 103 insertions(+), 15 deletions(-)
> 
> --
> 2.25.1
> 
> ---
> Arun R Murthy (5):
>       drm/plane: Add new plane property IN_FORMATS_ASYNC
>       drm/plane: Expose function to create format/modifier blob
>       drm/plane: Function to check async supported modifier/format
>       drm/i915/display: Populate list of async supported formats/modifiers
>       drm/i915/display: Add function for format_mod_supported_async
> 
>  drivers/gpu/drm/drm_mode_config.c                  |   7 ++
>  drivers/gpu/drm/drm_plane.c                        |  72 +++++++++----
>  drivers/gpu/drm/i915/display/skl_universal_plane.c | 113 ++++++++++++++++++---
>  include/drm/drm_mode_config.h                      |   6 ++
>  include/drm/drm_plane.h                            |  24 +++++
>  5 files changed, 188 insertions(+), 34 deletions(-)
> ---
> base-commit: 08bd590935a5258ffd79355c59adffd72fb2c642
> change-id: 20250102-asyn-bf76730501cc
> 
> Best regards,
> --
> Arun R Murthy <arun.r.murthy@intel.com>
> 
> ---
> Changes in v6:
> - EDITME: describe what is new in this series revision.
> - EDITME: use bulletpoints and terse descriptions.
> - Link to v5: https://lore.kernel.org/r/20250218-asyn-v5-0-7ac5ac4abd4a@intel.com
> 
> ---
> Arun R Murthy (3):
>       drm/plane: Add new plane property IN_FORMATS_ASYNC
>       drm/plane: modify create_in_formats to accommodate async
>       drm/i915/display: Add i915 hook for format_mod_supported_async
> 
>  drivers/gpu/drm/drm_mode_config.c                  |  7 +++
>  drivers/gpu/drm/drm_plane.c                        | 53 +++++++++++++++-----
>  drivers/gpu/drm/i915/display/skl_universal_plane.c | 56 ++++++++++++++++------
>  include/drm/drm_mode_config.h                      |  6 +++
>  include/drm/drm_plane.h                            | 17 +++++++
>  5 files changed, 112 insertions(+), 27 deletions(-)
> ---
> base-commit: bc7a84cbc968ce97e581e9e3c2d26fb0ac106482
> change-id: 20250102-asyn-bf76730501cc
> 
> Best regards,
> -- 
> Arun R Murthy <arun.r.murthy@intel.com>
> 

-- 
Simona Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch