Re: [Intel-gfx] [PATCH 2/4] drm/i915: Introduce do_async_flip flag to intel_plane_state

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Jan 18, 2022 at 12:48:37PM +0200, Stanislav Lisovskiy wrote:
> There might be various logical contructs when we might want
> to enable async flip, so lets calculate those and set this
> flag, so that there is no need in long conditions in other
> places.
> 
> v2: - Set do_async_flip flag to False, if no async flip needed.
>       Lets not rely that it will be 0-initialized, but set
>       explicitly, so that the logic is clear as well.
> 
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_atomic_plane.c  | 2 +-
>  drivers/gpu/drm/i915/display/intel_display.c       | 5 +++++
>  drivers/gpu/drm/i915/display/intel_display_types.h | 3 +++
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> index d1344e9c06de..87bad665a2c8 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> @@ -491,7 +491,7 @@ void intel_plane_update_arm(struct intel_plane *plane,
>  
>  	trace_intel_plane_update_arm(&plane->base, crtc);
>  
> -	if (crtc_state->uapi.async_flip && plane->async_flip)
> +	if (plane_state->do_async_flip)
>  		plane->async_flip(plane, crtc_state, plane_state, true);
>  	else
>  		plane->update_arm(plane, crtc_state, plane_state);
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 0964b2403e2d..f3ce29c42bc3 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -5027,6 +5027,11 @@ int intel_plane_atomic_calc_changes(const struct intel_crtc_state *old_crtc_stat
>  			 needs_scaling(new_plane_state))))
>  		new_crtc_state->disable_lp_wm = true;
>  
> +	if (new_crtc_state->uapi.async_flip && plane->async_flip)
> +		new_plane_state->do_async_flip = true;
> +	else
> +		new_plane_state->do_async_flip = false;

Clearing the flag should probably be in intel_plane_duplicate_state().

The decision to call intel_crtc_{enable,disable}_flip_done() should
also be based on do_async_flip, otherwise we're going to try to complete
the flip using two different mechanisms when we decide to do a sync flip
instead of an async flip.

Otherwise lgtm.

> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 41e3dd25a78f..6b107872ad39 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -634,6 +634,9 @@ struct intel_plane_state {
>  
>  	struct intel_fb_view view;
>  
> +	/* Indicates if async flip is required */
> +	bool do_async_flip;
> +
>  	/* Plane pxp decryption state */
>  	bool decrypt;
>  
> -- 
> 2.24.1.485.gad05a3d8e5

-- 
Ville Syrjälä
Intel