drm/i915: make asle notifications update backlight on all connectors

ALthough usually there's only one connector that supports backlight,
this also finds the correct connector. Before, we only updated the
connector on pipe A, which might not be the one with backlight. (This
only made a difference on BYT.)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_drv.h

@@ -159,6 +159,7 @@ struct intel_panel {
 
 	/* backlight */
 	struct {
+		bool present;
 		u32 level;
 		bool enabled;
 		struct backlight_device *device;

drivers/gpu/drm/i915/intel_opregion.c

@@ -396,13 +396,10 @@ int intel_opregion_notify_adapter(struct drm_device *dev, pci_power_t state)
 static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct drm_encoder *encoder;
 	struct drm_connector *connector;
-	struct intel_connector *intel_connector = NULL;
-	struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[0];
+	struct intel_connector *intel_connector;
+	struct intel_panel *panel;
 	struct opregion_asle __iomem *asle = dev_priv->opregion.asle;
-	u32 ret = 0;
-	bool found = false;
 
 	DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
 
@@ -414,38 +411,24 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 		return ASLC_BACKLIGHT_FAILED;
 
 	mutex_lock(&dev->mode_config.mutex);
+
 	/*
-	 * Could match the OpRegion connector here instead, but we'd also need
-	 * to verify the connector could handle a backlight call.
+	 * Update backlight on all connectors that support backlight (usually
+	 * only one).
 	 */
-	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
-		if (encoder->crtc == crtc) {
-			found = true;
-			break;
-		}
-
-	if (!found) {
-		ret = ASLC_BACKLIGHT_FAILED;
-		goto out;
-	}
-
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
-		if (connector->encoder == encoder)
-			intel_connector = to_intel_connector(connector);
-
-	if (!intel_connector) {
-		ret = ASLC_BACKLIGHT_FAILED;
-		goto out;
-	}
-
 	DRM_DEBUG_KMS("updating opregion backlight %d/255\n", bclp);
-	intel_panel_set_backlight(intel_connector, bclp, 255);
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		intel_connector = to_intel_connector(connector);
+		panel = &intel_connector->panel;
+		if (panel->backlight.present)
+			intel_panel_set_backlight(intel_connector, bclp, 255);
+	}
 	iowrite32(DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID, &asle->cblv);
 
-out:
 	mutex_unlock(&dev->mode_config.mutex);
 
-	return ret;
+
+	return 0;
 }
 
 static u32 asle_set_als_illum(struct drm_device *dev, u32 alsi)

drivers/gpu/drm/i915/intel_panel.c

@@ -844,13 +844,17 @@ int intel_panel_setup_backlight(struct drm_connector *connector)
 
 	intel_backlight_device_register(intel_connector);
 
+	panel->backlight.present = true;
+
 	return 0;
 }
 
 void intel_panel_destroy_backlight(struct drm_connector *connector)
 {
 	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_panel *panel = &intel_connector->panel;
 
+	panel->backlight.present = false;
 	intel_backlight_device_unregister(intel_connector);
 }