drm/i915: Split color mgmt based on single vs. double buffered registers

Split the color management hooks along the single vs. double
buffered registers line. Of the currently programmed registers
GAMMA_MODE and the ilk+ pipe CSC are double buffered, the
LUTS and CHV CGM block are single buffered.

The double buffered register will be programmed during the
normal pipe update with evasion, and also during pipe enable
so that the settings will already be correct when the pipe
starts up before the planes are enabled.

The single buffered registers are currently programmed before
the vblank evade. Which is totally wrong, but we'll correct
that later.

v2: Add some docs to explain the two vfuncs (Matt,Uma)
    Rebase
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205160848.24662-6-ville.syrjala@linux.intel.comReviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drivers/gpu/drm/i915/i915_drv.h

@@ -323,7 +323,19 @@ struct drm_i915_display_funcs {
 	/* display clock increase/decrease */
 	/* pll clock increase/decrease */
 
-	void (*load_csc_matrix)(const struct intel_crtc_state *crtc_state);
+	/*
+	 * Program double buffered color management registers during
+	 * vblank evasion. The registers should then latch during the
+	 * next vblank start, alongside any other double buffered registers
+	 * involved with the same commit.
+	 */
+	void (*color_commit)(const struct intel_crtc_state *crtc_state);
+	/*
+	 * Load LUTs (and other single buffered color management
+	 * registers). Will (hopefully) be called during the vblank
+	 * following the latching of any double buffered registers
+	 * involved with the same commit.
+	 */
 	void (*load_luts)(const struct intel_crtc_state *crtc_state);
 };
 

drivers/gpu/drm/i915/intel_color.c

@@ -304,14 +304,6 @@ static void cherryview_load_csc_matrix(const struct intel_crtc_state *crtc_state
 	I915_WRITE(CGM_PIPE_MODE(pipe), mode);
 }
 
-void intel_color_set_csc(const struct intel_crtc_state *crtc_state)
-{
-	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
-
-	if (dev_priv->display.load_csc_matrix)
-		dev_priv->display.load_csc_matrix(crtc_state);
-}
-
 /* Loads the legacy palette/gamma unit for the CRTC. */
 static void i9xx_load_luts_internal(const struct intel_crtc_state *crtc_state,
 				    const struct drm_property_blob *blob)
@@ -359,6 +351,16 @@ static void i9xx_load_luts(const struct intel_crtc_state *crtc_state)
 	i9xx_load_luts_internal(crtc_state, crtc_state->base.gamma_lut);
 }
 
+static void hsw_color_commit(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);
+
+	I915_WRITE(GAMMA_MODE(crtc->pipe), crtc_state->gamma_mode);
+
+	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)
 {
@@ -376,8 +378,6 @@ static void haswell_load_luts(const struct intel_crtc_state *crtc_state)
 		reenable_ips = true;
 	}
 
-	I915_WRITE(GAMMA_MODE(crtc->pipe), crtc_state->gamma_mode);
-
 	i9xx_load_luts(crtc_state);
 
 	if (reenable_ips)
@@ -485,8 +485,6 @@ static void broadwell_load_luts(const struct intel_crtc_state *crtc_state)
 		 */
 		I915_WRITE(PREC_PAL_INDEX(pipe), 0);
 	}
-
-	I915_WRITE(GAMMA_MODE(pipe), crtc_state->gamma_mode);
 }
 
 static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state)
@@ -539,8 +537,6 @@ static void glk_load_luts(const struct intel_crtc_state *crtc_state)
 		 */
 		I915_WRITE(PREC_PAL_INDEX(pipe), 0);
 	}
-
-	I915_WRITE(GAMMA_MODE(pipe), crtc_state->gamma_mode);
 }
 
 static void cherryview_load_luts(const struct intel_crtc_state *crtc_state)
@@ -551,10 +547,9 @@ static void cherryview_load_luts(const struct intel_crtc_state *crtc_state)
 	const struct drm_property_blob *degamma_lut = crtc_state->base.degamma_lut;
 	enum pipe pipe = crtc->pipe;
 
+	cherryview_load_csc_matrix(crtc_state);
+
 	if (crtc_state_is_legacy_gamma(crtc_state)) {
-		/* Turn off degamma/gamma on CGM block. */
-		I915_WRITE(CGM_PIPE_MODE(pipe),
-			   (crtc_state->base.ctm ? CGM_PIPE_MODE_CSC : 0));
 		i9xx_load_luts_internal(crtc_state, gamma_lut);
 		return;
 	}
@@ -595,11 +590,6 @@ static void cherryview_load_luts(const struct intel_crtc_state *crtc_state)
 		}
 	}
 
-	I915_WRITE(CGM_PIPE_MODE(pipe),
-		   (crtc_state->base.ctm ? CGM_PIPE_MODE_CSC : 0) |
-		   (degamma_lut ? CGM_PIPE_MODE_DEGAMMA : 0) |
-		   (gamma_lut ? CGM_PIPE_MODE_GAMMA : 0));
-
 	/*
 	 * Also program a linear LUT in the legacy block (behind the
 	 * CGM block).
@@ -614,6 +604,14 @@ void intel_color_load_luts(const struct intel_crtc_state *crtc_state)
 	dev_priv->display.load_luts(crtc_state);
 }
 
+void intel_color_commit(const struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
+
+	if (dev_priv->display.color_commit)
+		dev_priv->display.color_commit(crtc_state);
+}
+
 static int check_lut_size(const struct drm_property_blob *lut, int expected)
 {
 	int len;
@@ -675,18 +673,17 @@ void intel_color_init(struct intel_crtc *crtc)
 	drm_mode_crtc_set_gamma_size(&crtc->base, 256);
 
 	if (IS_CHERRYVIEW(dev_priv)) {
-		dev_priv->display.load_csc_matrix = cherryview_load_csc_matrix;
 		dev_priv->display.load_luts = cherryview_load_luts;
 	} else if (IS_HASWELL(dev_priv)) {
-		dev_priv->display.load_csc_matrix = ilk_load_csc_matrix;
 		dev_priv->display.load_luts = haswell_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)) {
-		dev_priv->display.load_csc_matrix = ilk_load_csc_matrix;
 		dev_priv->display.load_luts = broadwell_load_luts;
+		dev_priv->display.color_commit = hsw_color_commit;
 	} else if (IS_GEMINILAKE(dev_priv) || IS_CANNONLAKE(dev_priv)) {
-		dev_priv->display.load_csc_matrix = ilk_load_csc_matrix;
 		dev_priv->display.load_luts = glk_load_luts;
+		dev_priv->display.color_commit = hsw_color_commit;
 	} else {
 		dev_priv->display.load_luts = i9xx_load_luts;
 	}

drivers/gpu/drm/i915/intel_display.c

@@ -5779,6 +5779,7 @@ static void ironlake_crtc_enable(struct intel_crtc_state *pipe_config,
 	 * clocks enabled
 	 */
 	intel_color_load_luts(pipe_config);
+	intel_color_commit(pipe_config);
 
 	if (dev_priv->display.initial_watermarks != NULL)
 		dev_priv->display.initial_watermarks(old_intel_state, pipe_config);
@@ -5888,8 +5889,6 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
 
 	haswell_set_pipemisc(pipe_config);
 
-	intel_color_set_csc(pipe_config);
-
 	intel_crtc->active = true;
 
 	/* Display WA #1180: WaDisableScalarClockGating: glk, cnl */
@@ -5908,6 +5907,7 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
 	 * clocks enabled
 	 */
 	intel_color_load_luts(pipe_config);
+	intel_color_commit(pipe_config);
 
 	if (INTEL_GEN(dev_priv) >= 11)
 		icl_set_pipe_chicken(intel_crtc);
@@ -6245,8 +6245,6 @@ static void valleyview_crtc_enable(struct intel_crtc_state *pipe_config,
 
 	i9xx_set_pipeconf(pipe_config);
 
-	intel_color_set_csc(pipe_config);
-
 	intel_crtc->active = true;
 
 	intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true);
@@ -6266,6 +6264,7 @@ static void valleyview_crtc_enable(struct intel_crtc_state *pipe_config,
 	i9xx_pfit_enable(pipe_config);
 
 	intel_color_load_luts(pipe_config);
+	intel_color_commit(pipe_config);
 
 	dev_priv->display.initial_watermarks(old_intel_state,
 					     pipe_config);
@@ -6322,6 +6321,7 @@ static void i9xx_crtc_enable(struct intel_crtc_state *pipe_config,
 	i9xx_pfit_enable(pipe_config);
 
 	intel_color_load_luts(pipe_config);
+	intel_color_commit(pipe_config);
 
 	if (dev_priv->display.initial_watermarks != NULL)
 		dev_priv->display.initial_watermarks(old_intel_state,
@@ -13742,10 +13742,8 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc,
 
 	if (!modeset &&
 	    (intel_cstate->base.color_mgmt_changed ||
-	     intel_cstate->update_pipe)) {
-		intel_color_set_csc(intel_cstate);
+	     intel_cstate->update_pipe))
 		intel_color_load_luts(intel_cstate);
-	}
 
 	/* Perform vblank evasion around commit operation */
 	intel_pipe_update_start(intel_cstate);
@@ -13753,6 +13751,10 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc,
 	if (modeset)
 		goto out;
 
+	if (intel_cstate->base.color_mgmt_changed ||
+	    intel_cstate->update_pipe)
+		intel_color_commit(intel_cstate);
+
 	if (intel_cstate->update_pipe)
 		intel_update_pipe_config(old_intel_cstate, intel_cstate);
 	else if (INTEL_GEN(dev_priv) >= 9)

drivers/gpu/drm/i915/intel_drv.h

@@ -2389,7 +2389,7 @@ int intel_plane_atomic_check_with_state(const struct intel_crtc_state *old_crtc_
 /* intel_color.c */
 void intel_color_init(struct intel_crtc *crtc);
 int intel_color_check(struct intel_crtc_state *crtc_state);
-void intel_color_set_csc(const struct intel_crtc_state *crtc_state);
+void intel_color_commit(const struct intel_crtc_state *crtc_state);
 void intel_color_load_luts(const struct intel_crtc_state *crtc_state);
 
 /* intel_lspcon.c */