[PATCH] drm/i915: avoid full modeset when changing the color range properties

[daniel.vetter at ffwll.ch (Daniel Vetter)]

Automatic color range selection was added in

commit 55bc60db5988c8366751d3d04dd690698a53412c
Author: Ville Syrj?l? <ville.syrjala at linux.intel.com>
Date:   Thu Jan 17 16:31:29 2013 +0200

    drm/i915: Add "Automatic" mode for the "Broadcast RGB" property

but that removed the check to avoid a full modeset if the value is
unchanged. Unfortunately X sets all properties with their current
value at start-up, resulting in some ugly flickering which shouldn't
be there.

Cc: Ville Syrj?l? <ville.syrjala at linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/intel_dp.c   | 8 ++++++++
 drivers/gpu/drm/i915/intel_hdmi.c | 8 ++++++++
 drivers/gpu/drm/i915/intel_sdvo.c | 8 ++++++++
 3 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 50a9d9f..be529da 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2666,6 +2666,9 @@ intel_dp_set_property(struct drm_connector *connector,
 	}
 
 	if (property == dev_priv->broadcast_rgb_property) {
+		bool old_auto = intel_dp->color_range_auto;
+		bool old_range = intel_dp->color_range;
+
 		switch (val) {
 		case INTEL_BROADCAST_RGB_AUTO:
 			intel_dp->color_range_auto = true;
@@ -2681,6 +2684,11 @@ intel_dp_set_property(struct drm_connector *connector,
 		default:
 			return -EINVAL;
 		}
+
+		if (old_auto == intel_dp->color_range_auto &&
+		    old_range == intel_dp->color_range)
+			return 0;
+
 		goto done;
 	}
 
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 3942041..40d5812 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -947,6 +947,9 @@ intel_hdmi_set_property(struct drm_connector *connector,
 	}
 
 	if (property == dev_priv->broadcast_rgb_property) {
+		bool old_auto = intel_hdmi->color_range_auto;
+		bool old_range = intel_hdmi->color_range;
+
 		switch (val) {
 		case INTEL_BROADCAST_RGB_AUTO:
 			intel_hdmi->color_range_auto = true;
@@ -962,6 +965,11 @@ intel_hdmi_set_property(struct drm_connector *connector,
 		default:
 			return -EINVAL;
 		}
+
+		if (old_auto == intel_hdmi->color_range_auto &&
+		    old_range == intel_hdmi->color_range)
+			return 0;
+
 		goto done;
 	}
 
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index a618a6a..c1f7e0a 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1930,6 +1930,9 @@ intel_sdvo_set_property(struct drm_connector *connector,
 	}
 
 	if (property == dev_priv->broadcast_rgb_property) {
+		bool old_auto = intel_sdvo->color_range_auto;
+		bool old_range = intel_sdvo->color_range;
+
 		switch (val) {
 		case INTEL_BROADCAST_RGB_AUTO:
 			intel_sdvo->color_range_auto = true;
@@ -1947,6 +1950,11 @@ intel_sdvo_set_property(struct drm_connector *connector,
 		default:
 			return -EINVAL;
 		}
+
+		if (old_auto == intel_sdvo->color_range_auto &&
+		    old_range == intel_sdvo->color_range)
+			return 0;
+
 		goto done;
 	}
 
-- 
1.7.11.7