[Intel-gfx] [PATCH] drm/i915: cache the EDID for eDP panels

[Chris Wilson]

They aren't going anywhere, and probing on DDC can cause the panel to
blank briefly, so read them up front and cache them for later queries.

Jesse's patch revamped. Gotta love those display_info.raw_edid = NULL!
---
 drivers/gpu/drm/i915/intel_dp.c    |   48 +++++++++++++++++++++++++++---------
 drivers/gpu/drm/i915/intel_drv.h   |    1 +
 drivers/gpu/drm/i915/intel_modes.c |   24 ++++++++++++------
 3 files changed, 54 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index eb57ec7..207e25f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -67,6 +67,7 @@ struct intel_dp {
 	struct drm_display_mode *panel_fixed_mode;  /* for eDP */
 	struct delayed_work panel_vdd_work;
 	bool want_panel_vdd;
+	struct edid *edid; /* cached for eDP */
 };
 
 /**
@@ -2095,26 +2096,50 @@ g4x_dp_detect(struct intel_dp *intel_dp)
 }
 
 static struct edid *
-intel_dp_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
+_drm_edid_duplicate(struct edid *edid)
+{
+	struct edid *copy;
+	int size;
+
+	if (edid == NULL)
+		return NULL;
+
+	size = EDID_LENGTH * (1 + edid->extensions);
+	*copy = kmalloc(size, GFP_KERNEL);
+	if (copy)
+		memcpy(copy, edid, size);
+
+	return copy;
+}
+
+static struct edid *
+intel_dp_get_edid(struct drm_connector *connector)
 {
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
-	struct edid	*edid;
+	struct edid *edid;
+
+	if (is_edp(intel_dp))
+		return _drm_edid_duplicate(intel_dp->edid);
 
 	ironlake_edp_panel_vdd_on(intel_dp);
-	edid = drm_get_edid(connector, adapter);
+	edid = drm_get_edid(connector, &intel_dp->adapter);
 	ironlake_edp_panel_vdd_off(intel_dp, false);
+
 	return edid;
 }
 
 static int
-intel_dp_get_edid_modes(struct drm_connector *connector, struct i2c_adapter *adapter)
+intel_dp_get_edid_modes(struct drm_connector *connector)
 {
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
-	int	ret;
+	struct edid *edid;
+	int ret;
+
+	edid = intel_dp_get_edid(intel_dp);
+	ret = intel_connector_attach_edid(connector, edid);
+	connector->display_info.raw_edid = NULL;
+	kfree(edid);
 
-	ironlake_edp_panel_vdd_on(intel_dp);
-	ret = intel_ddc_get_modes(connector, adapter);
-	ironlake_edp_panel_vdd_off(intel_dp, false);
 	return ret;
 }
 
@@ -2172,7 +2197,7 @@ static int intel_dp_get_modes(struct drm_connector *connector)
 	/* We should parse the EDID data and find out if it has an audio sink
 	 */
 
-	ret = intel_dp_get_edid_modes(connector, &intel_dp->adapter);
+	ret = intel_dp_get_edid_modes(connector);
 	if (ret) {
 		if (is_edp(intel_dp) && !intel_dp->panel_fixed_mode) {
 			struct drm_display_mode *newmode;
@@ -2485,6 +2510,8 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 			break;
 	}
 
+	intel_dp_i2c_init(intel_dp, intel_connector, name);
+
 	/* Cache some DPCD data in the eDP case */
 	if (is_edp(intel_dp)) {
 		bool ret;
@@ -2543,6 +2570,7 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 
 		ironlake_edp_panel_vdd_on(intel_dp);
 		ret = intel_dp_get_dpcd(intel_dp);
+		intel_dp->edid = drm_get_edid(connector, &intel_dp->adapter);
 		ironlake_edp_panel_vdd_off(intel_dp, false);
 
 		if (ret) {
@@ -2559,8 +2587,6 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 		}
 	}
 
-	intel_dp_i2c_init(intel_dp, intel_connector, name);
-
 	intel_encoder->hot_plug = intel_dp_hot_plug;
 
 	if (is_edp(intel_dp)) {
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 3e09188..316413d 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -336,6 +336,7 @@ struct intel_fbc_work {
 
 int intel_ddc_get_modes(struct drm_connector *c, struct i2c_adapter *adapter);
 extern bool intel_ddc_probe(struct intel_encoder *intel_encoder, int ddc_bus);
+int intel_connector_attach_edid(struct drm_connector *connector, struct edid *edid);
 
 extern void intel_attach_force_audio_property(struct drm_connector *connector);
 extern void intel_attach_broadcast_rgb_property(struct drm_connector *connector);
diff --git a/drivers/gpu/drm/i915/intel_modes.c b/drivers/gpu/drm/i915/intel_modes.c
index d67ec3a..089ed8b 100644
--- a/drivers/gpu/drm/i915/intel_modes.c
+++ b/drivers/gpu/drm/i915/intel_modes.c
@@ -60,6 +60,18 @@ bool intel_ddc_probe(struct intel_encoder *intel_encoder, int ddc_bus)
 			    msgs, 2) == 2;
 }
 
+int intel_connector_attach_edid(struct drm_connector *connector,
+				struct edid *edid)
+{
+	int ret;
+
+	drm_mode_connector_update_edid_property(connector, edid);
+	ret = drm_add_edid_modes(connector, edid);
+	drm_edid_to_eld(connector, edid);
+
+	return ret;
+}
+
 /**
  * intel_ddc_get_modes - get modelist from monitor
  * @connector: DRM connector device to use
@@ -71,16 +83,12 @@ int intel_ddc_get_modes(struct drm_connector *connector,
 			struct i2c_adapter *adapter)
 {
 	struct edid *edid;
-	int ret = 0;
+	int ret;
 
 	edid = drm_get_edid(connector, adapter);
-	if (edid) {
-		drm_mode_connector_update_edid_property(connector, edid);
-		ret = drm_add_edid_modes(connector, edid);
-		drm_edid_to_eld(connector, edid);
-		connector->display_info.raw_edid = NULL;
-		kfree(edid);
-	}
+	ret = intel_connector_attach_edid(connector, edid);
+	connector->display_info.raw_edid = NULL;
+	kfree(edid);
 
 	return ret;
 }
-- 
1.7.10