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.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1ca96376651b..08d75d57b34e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/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);
 };