drm/i915: Move the async_flip bit setup into the .async_flip() hook

Set up the async flip PLANE_CTL bit directly in the
.async_flip() hook. Neither .update_plane() nor .disable_plane()
ever need to set this so having it done by skl_plane_ctl_crtc()
is rather pointless.

Cc: Karthik B S <karthik.b.s@intel.com>
Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111163711.12913-7-ville.syrjala@linux.intel.comReviewed-by: Karthik B S <karthik.b.s@intel.com>

drivers/gpu/drm/i915/display/intel_display.c

@@ -3429,9 +3429,6 @@ u32 skl_plane_ctl_crtc(const struct intel_crtc_state *crtc_state)
 	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
 	u32 plane_ctl = 0;
 
-	if (crtc_state->uapi.async_flip)
-		plane_ctl |= PLANE_CTL_ASYNC_FLIP;
-
 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
 		return plane_ctl;
 

drivers/gpu/drm/i915/display/intel_sprite.c

@@ -782,6 +782,8 @@ skl_plane_async_flip(struct intel_plane *plane,
 
 	plane_ctl |= skl_plane_ctl_crtc(crtc_state);
 
+	plane_ctl |= PLANE_CTL_ASYNC_FLIP;
+
 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
 	intel_de_write_fw(dev_priv, PLANE_CTL(pipe, plane_id), plane_ctl);