drm/i915: make backlight functions take a connector

On VLV/BYT, backlight controls a per-pipe, so when adjusting the
backlight we need to pass the correct info.  So make the externally
visible backlight functions take a connector argument, which can be used
internally to figure out the pipe backlight to adjust.

v2: make connector pipe lookup check for NULL crtc (Jani)
    fixup connector check in ASLE code (Jani)
v3: make sure we take the mode config lock around lookups (Daniel)
v4: fix double unlock in panel_get_brightness (Daniel)
v5: push ASLE work into a work queue (Daniel)
v6: separate ASLE work to a prep patch, rebase (Jani)

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 36 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 892d520175d..91b68dca064 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -396,7 +396,13 @@ 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 opregion_asle __iomem *asle = dev_priv->opregion.asle;
+	u32 ret = 0;
+	bool found = false;
 
 	DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
 
@@ -407,11 +413,39 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 	if (bclp > 255)
 		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.
+	 */
+	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(dev, bclp, 255);
+	intel_panel_set_backlight(intel_connector, bclp, 255);
 	iowrite32(DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID, &asle->cblv);
 
-	return 0;
+out:
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return ret;
 }
 
 static u32 asle_set_als_illum(struct drm_device *dev, u32 alsi)