[CI v2 2/4] drm/i915/display: Use async flip when available for initial plane config

[Lucas De Marchi]

On Fri, Oct 18, 2024 at 07:06:29PM +0200, Maarten Lankhorst wrote:
>I'm planning to reorder readout in the Xe sequence in such a way that
>interrupts will not be available, so just use an async flip.
>
>Since the new FB points to the same pages, it will not tear. It also
>has the benefit of perhaps being slightly faster.
>
>Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

Ville was against using async flip here. Anything changed?

Lucas De Marchi

>---
> drivers/gpu/drm/i915/display/skl_universal_plane.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
>index a0a7ed01415a5..6740c193920ff 100644
>--- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
>+++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
>@@ -2902,7 +2902,7 @@ bool skl_fixup_initial_plane_config(struct intel_crtc *crtc,
> 		to_intel_plane_state(plane->base.state);
> 	enum plane_id plane_id = plane->id;
> 	enum pipe pipe = crtc->pipe;
>-	u32 base;
>+	u32 base, plane_ctl;
>
> 	if (!plane_state->uapi.visible)
> 		return false;
>@@ -2916,7 +2916,16 @@ bool skl_fixup_initial_plane_config(struct intel_crtc *crtc,
> 	if (plane_config->base == base)
> 		return false;
>
>+	/* Perform an async flip to the new surface. */
>+	plane_ctl = intel_de_read(i915, PLANE_CTL(pipe, plane_id));
>+	plane_ctl |= PLANE_CTL_ASYNC_FLIP;
>+
>+	intel_de_write(i915, PLANE_CTL(pipe, plane_id), plane_ctl);
> 	intel_de_write(i915, PLANE_SURF(pipe, plane_id), base);
>
>-	return true;
>+	if (intel_de_wait(i915, PLANE_SURFLIVE(pipe, plane_id), ~0U, base, 40) < 0)
>+		drm_warn(&i915->drm, "async flip timed out\n");
>+
>+	/* No need to vblank wait either */
>+	return false;
> }
>-- 
>2.45.2
>