[Intel-gfx] [PATCH v4 7/8] drm/i915: Do not compute watermarks on a noop.

[Maarten Lankhorst]

No atomic state should be included after all validation when nothing has
changed. During modeset all active planes will be added to the state,
while disabled planes won't change their state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |  3 +-
 drivers/gpu/drm/i915/intel_drv.h     | 13 ++++++++
 drivers/gpu/drm/i915/intel_pm.c      | 61 +++++++++++++++++++++---------------
 3 files changed, 51 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 00cb261c6787..6bb1f5dbc7a0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11910,7 +11910,8 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
 	}
 
 	ret = 0;
-	if (dev_priv->display.compute_pipe_wm) {
+	if (dev_priv->display.compute_pipe_wm &&
+	    (mode_changed || pipe_config->update_pipe || crtc_state->planes_changed)) {
 		ret = dev_priv->display.compute_pipe_wm(intel_crtc, state);
 		if (ret)
 			return ret;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 8effb9ece21e..144597ac74e3 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1583,6 +1583,19 @@ intel_atomic_get_crtc_state(struct drm_atomic_state *state,
 
 	return to_intel_crtc_state(crtc_state);
 }
+
+static inline struct intel_plane_state *
+intel_atomic_get_existing_plane_state(struct drm_atomic_state *state,
+				      struct intel_plane *plane)
+{
+	struct drm_plane_state *plane_state;
+
+	plane_state = drm_atomic_get_existing_plane_state(state, &plane->base);
+
+	return to_intel_plane_state(plane_state);
+}
+
+
 int intel_atomic_setup_scalers(struct drm_device *dev,
 	struct intel_crtc *intel_crtc,
 	struct intel_crtc_state *crtc_state);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 379eabe093cb..8fb8c6891ae6 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2010,11 +2010,18 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
 		cur_latency *= 5;
 	}
 
-	result->pri_val = ilk_compute_pri_wm(cstate, pristate,
-					     pri_latency, level);
-	result->spr_val = ilk_compute_spr_wm(cstate, sprstate, spr_latency);
-	result->cur_val = ilk_compute_cur_wm(cstate, curstate, cur_latency);
-	result->fbc_val = ilk_compute_fbc_wm(cstate, pristate, result->pri_val);
+	if (pristate) {
+		result->pri_val = ilk_compute_pri_wm(cstate, pristate,
+						     pri_latency, level);
+		result->fbc_val = ilk_compute_fbc_wm(cstate, pristate, result->pri_val);
+	}
+
+	if (sprstate)
+		result->spr_val = ilk_compute_spr_wm(cstate, sprstate, spr_latency);
+
+	if (curstate)
+		result->cur_val = ilk_compute_cur_wm(cstate, curstate, cur_latency);
+
 	result->enable = true;
 }
 
@@ -2287,7 +2294,6 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
 	const struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc_state *cstate = NULL;
 	struct intel_plane *intel_plane;
-	struct drm_plane_state *ps;
 	struct intel_plane_state *pristate = NULL;
 	struct intel_plane_state *sprstate = NULL;
 	struct intel_plane_state *curstate = NULL;
@@ -2306,30 +2312,37 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
 	memset(pipe_wm, 0, sizeof(*pipe_wm));
 
 	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
-		ps = drm_atomic_get_plane_state(state,
-						&intel_plane->base);
-		if (IS_ERR(ps))
-			return PTR_ERR(ps);
+		struct intel_plane_state *ps;
+
+		ps = intel_atomic_get_existing_plane_state(state,
+							   intel_plane);
+		if (!ps)
+			continue;
 
 		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
-			pristate = to_intel_plane_state(ps);
-		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
-			sprstate = to_intel_plane_state(ps);
-		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
-			curstate = to_intel_plane_state(ps);
+			pristate = ps;
+		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY) {
+			sprstate = ps;
+
+			if (ps) {
+				pipe_wm->sprites_enabled = sprstate->visible;
+				pipe_wm->sprites_scaled = sprstate->visible &&
+					(drm_rect_width(&sprstate->dst) != drm_rect_width(&sprstate->src) >> 16 ||
+					drm_rect_height(&sprstate->dst) != drm_rect_height(&sprstate->src) >> 16);
+			}
+		} else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
+			curstate = ps;
 	}
 
-	config.sprites_enabled = sprstate->visible;
-	config.sprites_scaled = sprstate->visible &&
-		(drm_rect_width(&sprstate->dst) != drm_rect_width(&sprstate->src) >> 16 ||
-		drm_rect_height(&sprstate->dst) != drm_rect_height(&sprstate->src) >> 16);
+	config.sprites_enabled = pipe_wm->sprites_enabled;
+	config.sprites_scaled = pipe_wm->sprites_scaled;
 
 	pipe_wm->pipe_enabled = cstate->base.active;
 	pipe_wm->sprites_enabled = config.sprites_enabled;
 	pipe_wm->sprites_scaled = config.sprites_scaled;
 
 	/* ILK/SNB: LP2+ watermarks only w/o sprites */
-	if (INTEL_INFO(dev)->gen <= 6 && sprstate->visible)
+	if (INTEL_INFO(dev)->gen <= 6 && pipe_wm->sprites_enabled)
 		max_level = 1;
 
 	/* ILK/SNB/IVB: LP1+ watermarks only w/o scaling */
@@ -2352,20 +2365,18 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
 	ilk_compute_wm_reg_maximums(dev, 1, &max);
 
 	for (level = 1; level <= max_level; level++) {
-		struct intel_wm_level wm = {};
+		struct intel_wm_level *wm = &pipe_wm->wm[level];
 
 		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
-				     pristate, sprstate, curstate, &wm);
+				     pristate, sprstate, curstate, wm);
 
 		/*
 		 * Disable any watermark level that exceeds the
 		 * register maximums since such watermarks are
 		 * always invalid.
 		 */
-		if (!ilk_validate_wm_level(level, &max, &wm))
+		if (!ilk_validate_wm_level(level, &max, wm))
 			break;
-
-		pipe_wm->wm[level] = wm;
 	}
 
 	return 0;
-- 
2.1.0