---

yaml
---
r: 234021
b: refs/heads/master
c: ba3820a
h: refs/heads/master
i:
  234019: 10de3b7
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 35d34df711e8b44846e759d8cfddb4ec6877cccb
+refs/heads/master: ba3820ade317ee36e496b9b40d2ec3987dd4aef0

trunk/drivers/gpu/drm/i915/i915_reg.h

@@ -1553,7 +1553,17 @@
 
 /* Backlight control */
 #define BLC_PWM_CTL		0x61254
+#define   BACKLIGHT_MODULATION_FREQ_SHIFT		(17)
 #define BLC_PWM_CTL2		0x61250 /* 965+ only */
+#define   BLM_COMBINATION_MODE (1 << 30)
+/*
+ * This is the most significant 15 bits of the number of backlight cycles in a
+ * complete cycle of the modulated backlight control.
+ *
+ * The actual value is this field multiplied by two.
+ */
+#define   BACKLIGHT_MODULATION_FREQ_MASK		(0x7fff << 17)
+#define   BLM_LEGACY_MODE				(1 << 16)
 /*
  * This is the number of cycles out of the backlight modulation cycle for which
  * the backlight is on.

trunk/drivers/gpu/drm/i915/intel_panel.c

@@ -30,6 +30,8 @@
 
 #include "intel_drv.h"
 
+#define PCI_LBPC 0xf4 /* legacy/combination backlight modes */
+
 void
 intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
 		       struct drm_display_mode *adjusted_mode)
@@ -110,6 +112,19 @@ intel_pch_panel_fitting(struct drm_device *dev,
 	dev_priv->pch_pf_size = (width << 16) | height;
 }
 
+static int is_backlight_combination_mode(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (INTEL_INFO(dev)->gen >= 4)
+		return I915_READ(BLC_PWM_CTL2) & BLM_COMBINATION_MODE;
+
+	if (IS_GEN2(dev))
+		return I915_READ(BLC_PWM_CTL) & BLM_LEGACY_MODE;
+
+	return 0;
+}
+
 static u32 i915_read_blc_pwm_ctl(struct drm_i915_private *dev_priv)
 {
 	u32 val;
@@ -166,6 +181,9 @@ u32 intel_panel_get_max_backlight(struct drm_device *dev)
 			if (INTEL_INFO(dev)->gen < 4)
 				max &= ~1;
 		}
+
+		if (is_backlight_combination_mode(dev))
+			max *= 0xff;
 	}
 
 	DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
@@ -183,6 +201,14 @@ u32 intel_panel_get_backlight(struct drm_device *dev)
 		val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
 		if (IS_PINEVIEW(dev))
 			val >>= 1;
+
+		if (is_backlight_combination_mode(dev)){
+			u8 lbpc;
+
+			val &= ~1;
+			pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
+			val *= lbpc;
+		}
 	}
 
 	DRM_DEBUG_DRIVER("get backlight PWM = %d\n", val);
@@ -205,6 +231,16 @@ void intel_panel_set_backlight(struct drm_device *dev, u32 level)
 
 	if (HAS_PCH_SPLIT(dev))
 		return intel_pch_panel_set_backlight(dev, level);
+
+	if (is_backlight_combination_mode(dev)){
+		u32 max = intel_panel_get_max_backlight(dev);
+		u8 lbpc;
+
+		lbpc = level * 0xfe / max + 1;
+		level /= lbpc;
+		pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
+	}
+
 	tmp = I915_READ(BLC_PWM_CTL);
 	if (IS_PINEVIEW(dev)) {
 		tmp &= ~(BACKLIGHT_DUTY_CYCLE_MASK - 1);