[Intel-gfx] [PATCH 07/13] drm/i915: Move LUT programming to happen after vblank waits

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The LUTs are single buffered so we should program them after
the double buffered pipe updates have been latched by the
hardware.

We'll also fix up the IPS vs. split gamma w/a to do the IPS
disable like everyone else. Note that this is currently dead
code as we don't use the split gamma mode on HSW, but that
will be fixed up shortly.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_color.c   | 25 +--------------
 drivers/gpu/drm/i915/intel_display.c | 47 ++++++++++++++++++++++++----
 2 files changed, 42 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
index f9e0855162f3..0c0da7ed0fd7 100644
--- a/drivers/gpu/drm/i915/intel_color.c
+++ b/drivers/gpu/drm/i915/intel_color.c
@@ -361,29 +361,6 @@ static void hsw_color_commit(const struct intel_crtc_state *crtc_state)
 	ilk_load_csc_matrix(crtc_state);
 }
 
-/* Loads the legacy palette/gamma unit for the CRTC on Haswell. */
-static void haswell_load_luts(const struct intel_crtc_state *crtc_state)
-{
-	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
-	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	bool reenable_ips = false;
-
-	/*
-	 * Workaround : Do not read or write the pipe palette/gamma data while
-	 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
-	 */
-	if (IS_HASWELL(dev_priv) && crtc_state->ips_enabled &&
-	    (crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)) {
-		hsw_disable_ips(crtc_state);
-		reenable_ips = true;
-	}
-
-	i9xx_load_luts(crtc_state);
-
-	if (reenable_ips)
-		hsw_enable_ips(crtc_state);
-}
-
 static void bdw_load_degamma_lut(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
@@ -660,7 +637,7 @@ void intel_color_init(struct intel_crtc *crtc)
 	if (IS_CHERRYVIEW(dev_priv)) {
 		dev_priv->display.load_luts = cherryview_load_luts;
 	} else if (IS_HASWELL(dev_priv)) {
-		dev_priv->display.load_luts = haswell_load_luts;
+		dev_priv->display.load_luts = i9xx_load_luts;
 		dev_priv->display.color_commit = hsw_color_commit;
 	} else if (IS_BROADWELL(dev_priv) || IS_GEN9_BC(dev_priv) ||
 		   IS_BROXTON(dev_priv)) {
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 96c78566b8e6..1caee4128974 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5299,24 +5299,54 @@ intel_pre_disable_primary_noatomic(struct drm_crtc *crtc)
 static bool hsw_pre_update_disable_ips(const struct intel_crtc_state *old_crtc_state,
 				       const struct intel_crtc_state *new_crtc_state)
 {
+	struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+
 	if (!old_crtc_state->ips_enabled)
 		return false;
 
 	if (needs_modeset(&new_crtc_state->base))
 		return true;
 
+	/*
+	 * Workaround : Do not read or write the pipe palette/gamma data while
+	 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
+	 *
+	 * Disable IPS before we program the LUT.
+	 */
+	if (IS_HASWELL(dev_priv) &&
+	    (new_crtc_state->base.color_mgmt_changed ||
+	     new_crtc_state->update_pipe) &&
+	    new_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)
+		return true;
+
 	return !new_crtc_state->ips_enabled;
 }
 
 static bool hsw_post_update_enable_ips(const struct intel_crtc_state *old_crtc_state,
 				       const struct intel_crtc_state *new_crtc_state)
 {
+	struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+
 	if (!new_crtc_state->ips_enabled)
 		return false;
 
 	if (needs_modeset(&new_crtc_state->base))
 		return true;
 
+	/*
+	 * Workaround : Do not read or write the pipe palette/gamma data while
+	 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
+	 *
+	 * Re-enable IPS after the LUT has been programmed.
+	 */
+	if (IS_HASWELL(dev_priv) &&
+	    (new_crtc_state->base.color_mgmt_changed ||
+	     new_crtc_state->update_pipe) &&
+	    new_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)
+		return true;
+
 	/*
 	 * We can't read out IPS on broadwell, assume the worst and
 	 * forcibly enable IPS on the first fastset.
@@ -11050,7 +11080,7 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
 			return ret;
 	}
 
-	if (crtc_state->color_mgmt_changed) {
+	if (mode_changed || crtc_state->color_mgmt_changed) {
 		ret = intel_color_check(pipe_config);
 		if (ret)
 			return ret;
@@ -13117,6 +13147,16 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 	 */
 	drm_atomic_helper_wait_for_flip_done(dev, state);
 
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		new_intel_crtc_state = to_intel_crtc_state(new_crtc_state);
+
+		if (new_crtc_state->active &&
+		    !needs_modeset(new_crtc_state) &&
+		    (new_intel_crtc_state->base.color_mgmt_changed ||
+		     new_intel_crtc_state->update_pipe))
+			intel_color_load_luts(new_intel_crtc_state);
+	}
+
 	/*
 	 * Now that the vblank has passed, we can go ahead and program the
 	 * optimal watermarks on platforms that need two-step watermark
@@ -13632,11 +13672,6 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc,
 		intel_atomic_get_new_crtc_state(old_intel_state, intel_crtc);
 	bool modeset = needs_modeset(&intel_cstate->base);
 
-	if (!modeset &&
-	    (intel_cstate->base.color_mgmt_changed ||
-	     intel_cstate->update_pipe))
-		intel_color_load_luts(intel_cstate);
-
 	/* Perform vblank evasion around commit operation */
 	intel_pipe_update_start(intel_cstate);
 
-- 
2.19.2