fix backlight brightness on intel LVDS panel after reopening lid

Commit Message

Alex Riesen Feb. 16, 2011, 7:26 p.m. UTC

None

Patch

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index c65992d..c4b1ca4 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -125,55 +125,15 @@  static int is_backlight_combination_mode(struct drm_device *dev)
 	return 0;
 }
 
-static u32 i915_read_blc_pwm_ctl(struct drm_i915_private *dev_priv)
-{
-	u32 val;
-
-	/* Restore the CTL value if it lost, e.g. GPU reset */
-
-	if (HAS_PCH_SPLIT(dev_priv->dev)) {
-		val = I915_READ(BLC_PWM_PCH_CTL2);
-		if (dev_priv->saveBLC_PWM_CTL2 == 0) {
-			dev_priv->saveBLC_PWM_CTL2 = val;
-		} else if (val == 0) {
-			I915_WRITE(BLC_PWM_PCH_CTL2,
-				   dev_priv->saveBLC_PWM_CTL);
-			val = dev_priv->saveBLC_PWM_CTL;
-		}
-	} else {
-		val = I915_READ(BLC_PWM_CTL);
-		if (dev_priv->saveBLC_PWM_CTL == 0) {
-			dev_priv->saveBLC_PWM_CTL = val;
-			dev_priv->saveBLC_PWM_CTL2 = I915_READ(BLC_PWM_CTL2);
-		} else if (val == 0) {
-			I915_WRITE(BLC_PWM_CTL,
-				   dev_priv->saveBLC_PWM_CTL);
-			I915_WRITE(BLC_PWM_CTL2,
-				   dev_priv->saveBLC_PWM_CTL2);
-			val = dev_priv->saveBLC_PWM_CTL;
-		}
-	}
-
-	return val;
-}
-
 u32 intel_panel_get_max_backlight(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 max;
 
-	max = i915_read_blc_pwm_ctl(dev_priv);
-	if (max == 0) {
-		/* XXX add code here to query mode clock or hardware clock
-		 * and program max PWM appropriately.
-		 */
-		printk_once(KERN_WARNING "fixme: max PWM is zero.\n");
-		return 1;
-	}
-
 	if (HAS_PCH_SPLIT(dev)) {
-		max >>= 16;
+		max = I915_READ(BLC_PWM_PCH_CTL2) >> 16;
 	} else {
+		max = I915_READ(BLC_PWM_CTL);
 		if (IS_PINEVIEW(dev)) {
 			max >>= 17;
 		} else {
@@ -186,6 +146,14 @@  u32 intel_panel_get_max_backlight(struct drm_device *dev)
 			max *= 0xff;
 	}
 
+	if (max == 0) {
+		/* XXX add code here to query mode clock or hardware clock
+		 * and program max PWM appropriately.
+		 */
+		DRM_ERROR("fixme: max PWM is zero.\n");
+		max = 1;
+	}
+
 	DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
 	return max;
 }
@@ -255,11 +223,11 @@  void intel_panel_disable_backlight(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	if (dev_priv->backlight_enabled) {
-		dev_priv->backlight_level = intel_panel_get_backlight(dev);
-		dev_priv->backlight_enabled = false;
-	}
+	if (!dev_priv->backlight_enabled)
+		return;
 
+	dev_priv->backlight_enabled = false;
+	dev_priv->backlight_level = intel_panel_get_backlight(dev);
 	intel_panel_set_backlight(dev, 0);
 }
 
@@ -267,6 +235,9 @@  void intel_panel_enable_backlight(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	if (dev_priv->backlight_enabled)
+		return;
+
 	if (dev_priv->backlight_level == 0)
 		dev_priv->backlight_level = intel_panel_get_max_backlight(dev);
 
@@ -278,6 +249,6 @@  void intel_panel_setup_backlight(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	dev_priv->backlight_level = intel_panel_get_backlight(dev);
+	dev_priv->backlight_level = intel_panel_get_max_backlight(dev);
 	dev_priv->backlight_enabled = dev_priv->backlight_level != 0;
 }