drm/i915/ivb: Move WaCxSRDisabledForSpriteScaling w/a to atomic check

Determine whether we need to apply this workaround at atomic check time
and just set a flag that will be used by the main watermark update
routine.

Moving this workaround into the atomic framework reduces
ilk_update_sprite_wm() to just a standard watermark update, so drop it
completely and just ensure that ilk_update_wm() is called whenever a
sprite plane is updated in a way that would affect watermarks.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Smoke-tested-by: Paulo Zanoni <przanoni@gmail.com>
Link: http://patchwork.freedesktop.org/patch/60367/

drivers/gpu/drm/i915/intel_atomic.c

@@ -94,6 +94,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc)
 	__drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->base);
 
 	crtc_state->update_pipe = false;
+	crtc_state->disable_lp_wm = false;
 
 	return &crtc_state->base;
 }

drivers/gpu/drm/i915/intel_display.c

@@ -11581,18 +11581,32 @@ retry:
 static bool intel_wm_need_update(struct drm_plane *plane,
 				 struct drm_plane_state *state)
 {
-	/* Update watermarks on tiling changes. */
+	struct intel_plane_state *new = to_intel_plane_state(state);
+	struct intel_plane_state *cur = to_intel_plane_state(plane->state);
+
+	/* Update watermarks on tiling or size changes. */
 	if (!plane->state->fb || !state->fb ||
 	    plane->state->fb->modifier[0] != state->fb->modifier[0] ||
-	    plane->state->rotation != state->rotation)
-		return true;
-
-	if (plane->state->crtc_w != state->crtc_w)
+	    plane->state->rotation != state->rotation ||
+	    drm_rect_width(&new->src) != drm_rect_width(&cur->src) ||
+	    drm_rect_height(&new->src) != drm_rect_height(&cur->src) ||
+	    drm_rect_width(&new->dst) != drm_rect_width(&cur->dst) ||
+	    drm_rect_height(&new->dst) != drm_rect_height(&cur->dst))
 		return true;
 
 	return false;
 }
 
+static bool needs_scaling(struct intel_plane_state *state)
+{
+	int src_w = drm_rect_width(&state->src) >> 16;
+	int src_h = drm_rect_height(&state->src) >> 16;
+	int dst_w = drm_rect_width(&state->dst);
+	int dst_h = drm_rect_height(&state->dst);
+
+	return (src_w != dst_w || src_h != dst_h);
+}
+
 int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 				    struct drm_plane_state *plane_state)
 {
@@ -11608,7 +11622,6 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 	bool mode_changed = needs_modeset(crtc_state);
 	bool was_crtc_enabled = crtc->state->active;
 	bool is_crtc_enabled = crtc_state->active;
-
 	bool turn_off, turn_on, visible, was_visible;
 	struct drm_framebuffer *fb = plane_state->fb;
 
@@ -11718,11 +11731,23 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 	case DRM_PLANE_TYPE_CURSOR:
 		break;
 	case DRM_PLANE_TYPE_OVERLAY:
-		if (turn_off && !mode_changed) {
+		/*
+		 * WaCxSRDisabledForSpriteScaling:ivb
+		 *
+		 * cstate->update_wm was already set above, so this flag will
+		 * take effect when we commit and program watermarks.
+		 */
+		if (IS_IVYBRIDGE(dev) &&
+		    needs_scaling(to_intel_plane_state(plane_state)) &&
+		    !needs_scaling(old_plane_state)) {
+			to_intel_crtc_state(crtc_state)->disable_lp_wm = true;
+		} else if (turn_off && !mode_changed) {
 			intel_crtc->atomic.wait_vblank = true;
 			intel_crtc->atomic.update_sprite_watermarks |=
 				1 << i;
 		}
+
+		break;
 	}
 	return 0;
 }

drivers/gpu/drm/i915/intel_drv.h

@@ -468,6 +468,9 @@ struct intel_crtc_state {
 
 	/* w/a for waiting 2 vblanks during crtc enable */
 	enum pipe hsw_workaround_pipe;
+
+	/* IVB sprite scaling w/a (WaCxSRDisabledForSpriteScaling:ivb) */
+	bool disable_lp_wm;
 };
 
 struct vlv_wm_state {

drivers/gpu/drm/i915/intel_pm.c

@@ -3674,6 +3674,18 @@ static void ilk_update_wm(struct drm_crtc *crtc)
 
 	WARN_ON(cstate->base.active != intel_crtc->active);
 
+	/*
+	 * IVB workaround: must disable low power watermarks for at least
+	 * one frame before enabling scaling.  LP watermarks can be re-enabled
+	 * when scaling is disabled.
+	 *
+	 * WaCxSRDisabledForSpriteScaling:ivb
+	 */
+	if (cstate->disable_lp_wm) {
+		ilk_disable_lp_wm(dev);
+		intel_wait_for_vblank(dev, intel_crtc->pipe);
+	}
+
 	intel_compute_pipe_wm(cstate, &pipe_wm);
 
 	if (!memcmp(&intel_crtc->wm.active, &pipe_wm, sizeof(pipe_wm)))
@@ -3705,28 +3717,6 @@ static void ilk_update_wm(struct drm_crtc *crtc)
 	ilk_write_wm_values(dev_priv, &results);
 }
 
-static void
-ilk_update_sprite_wm(struct drm_plane *plane,
-		     struct drm_crtc *crtc,
-		     uint32_t sprite_width, uint32_t sprite_height,
-		     int pixel_size, bool enabled, bool scaled)
-{
-	struct drm_device *dev = plane->dev;
-	struct intel_plane *intel_plane = to_intel_plane(plane);
-
-	/*
-	 * IVB workaround: must disable low power watermarks for at least
-	 * one frame before enabling scaling.  LP watermarks can be re-enabled
-	 * when scaling is disabled.
-	 *
-	 * WaCxSRDisabledForSpriteScaling:ivb
-	 */
-	if (IS_IVYBRIDGE(dev) && scaled && ilk_disable_lp_wm(dev))
-		intel_wait_for_vblank(dev, intel_plane->pipe);
-
-	ilk_update_wm(crtc);
-}
-
 static void skl_pipe_wm_active_state(uint32_t val,
 				     struct skl_pipe_wm *active,
 				     bool is_transwm,
@@ -7040,7 +7030,6 @@ void intel_init_pm(struct drm_device *dev)
 		    (!IS_GEN5(dev) && dev_priv->wm.pri_latency[0] &&
 		     dev_priv->wm.spr_latency[0] && dev_priv->wm.cur_latency[0])) {
 			dev_priv->display.update_wm = ilk_update_wm;
-			dev_priv->display.update_sprite_wm = ilk_update_sprite_wm;
 		} else {
 			DRM_DEBUG_KMS("Failed to read display plane latency. "
 				      "Disable CxSR\n");