[Intel-gfx] [PATCH 08/25] drm/i915/fbc: unconditionally update FBC during atomic commits

[Paulo Zanoni]

We unconditionally disable/update FBC even during the page flip
IOCTLs, and an unconditional disable/update at every atomic commit
touching the primary plane shouldn't impact PC state residency
noticeably. Besides, the code that checks for rotation is a good hint
that we may be forgetting something else, so let's leave all the
decisions to intel_fbc.c, making the code much safer.

Once we have the code to properly make FBC enable/update decisions
based on atomic states, with proper locking, then we'll be able to
evaluate whether it will be worth trying to optimize the cases where a
disable isn't needed.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 22 ++--------------------
 1 file changed, 2 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f026ade..baab41046 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11928,6 +11928,8 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 	case DRM_PLANE_TYPE_PRIMARY:
 		intel_crtc->atomic.pre_disable_primary = turn_off;
 		intel_crtc->atomic.post_enable_primary = turn_on;
+		intel_crtc->atomic.disable_fbc = true;
+		intel_crtc->atomic.update_fbc = true;
 
 		if (turn_off) {
 			/*
@@ -11939,28 +11941,9 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 			 * disable.
 			 */
 			intel_crtc->atomic.disable_ips = true;
-
-			intel_crtc->atomic.disable_fbc = true;
 		}
 
 		/*
-		 * FBC does not work on some platforms for rotated
-		 * planes, so disable it when rotation is not 0 and
-		 * update it when rotation is set back to 0.
-		 *
-		 * FIXME: This is redundant with the fbc update done in
-		 * the primary plane enable function except that that
-		 * one is done too late. We eventually need to unify
-		 * this.
-		 */
-
-		if (visible &&
-		    INTEL_INFO(dev)->gen <= 4 && !IS_G4X(dev) &&
-		    dev_priv->fbc.crtc == intel_crtc &&
-		    plane_state->rotation != BIT(DRM_ROTATE_0))
-			intel_crtc->atomic.disable_fbc = true;
-
-		/*
 		 * BDW signals flip done immediately if the plane
 		 * is disabled, even if the plane enable is already
 		 * armed to occur at the next vblank :(
@@ -11968,7 +11951,6 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 		if (turn_on && IS_BROADWELL(dev))
 			intel_crtc->atomic.wait_vblank = true;
 
-		intel_crtc->atomic.update_fbc |= visible || mode_changed;
 		break;
 	case DRM_PLANE_TYPE_CURSOR:
 		break;
-- 
2.6.4