drm/i915: Update legacy primary state outside the commit hook, v2.

This should allow not running plane commit when the crtc is off.
While the atomic helpers update those, crtc->x/y is only updated
during modesets, and primary plane is updated after this function
returns.

Unfortunately non-atomic watermarks and fbc still depend on this
state inside i915, so it has to be kept in sync.

Changes since v1:
- Add comment that the legacy state is updated for fbc.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -12213,6 +12213,18 @@ intel_modeset_update_crtc_state(struct drm_atomic_state *state)
 			crtc->hwmode = crtc->state->adjusted_mode;
 		else
 			crtc->hwmode.crtc_clock = 0;
+
+		/*
+		 * Update legacy state to satisfy fbc code. This can
+		 * be removed when fbc uses the atomic state.
+		 */
+		if (drm_atomic_get_existing_plane_state(state, crtc->primary)) {
+			struct drm_plane_state *plane_state = crtc->primary->state;
+
+			crtc->primary->fb = plane_state->fb;
+			crtc->x = plane_state->src_x >> 16;
+			crtc->y = plane_state->src_y >> 16;
+		}
 	}
 }
 
@@ -13457,15 +13469,8 @@ intel_commit_primary_plane(struct drm_plane *plane,
 	struct drm_framebuffer *fb = state->base.fb;
 	struct drm_device *dev = plane->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_crtc *intel_crtc;
-	struct drm_rect *src = &state->src;
 
 	crtc = crtc ? crtc : plane->crtc;
-	intel_crtc = to_intel_crtc(crtc);
-
-	plane->fb = fb;
-	crtc->x = src->x1 >> 16;
-	crtc->y = src->y1 >> 16;
 
 	if (!crtc->state->active)
 		return;