[PATCH 1/4] drm/i915: clock gating fix for gen5 and gen6

[Zhenyu Wang <zhenyuw@linux.intel.com>]

Some bits should only be set when enable FBC.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h      |    4 +++-
 drivers/gpu/drm/i915/intel_display.c |   27 ++++++++++++++-------------
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2abe240..b0aabe4 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2771,8 +2771,10 @@
 #define  ILK_eDP_A_DISABLE		(1<<24)
 #define  ILK_DESKTOP			(1<<23)
 #define ILK_DSPCLK_GATE		0x42020
-#define  ILK_DPARB_CLK_GATE	(1<<5)
+#define  ILK_DPFC_CLK_GATE	(1<<9)
+#define  ILK_DPFCR_CLK_GATE	(1<<8)
 #define  ILK_DPFD_CLK_GATE	(1<<7)
+#define  ILK_DPARB_CLK_GATE	(1<<5)
 
 /* According to spec this bit 7/8/9 of 0x42020 should be set to enable FBC */
 #define   ILK_CLK_FBC		(1<<7)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 49fb54f..b7d1101 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6452,7 +6452,7 @@ void intel_enable_clock_gating(struct drm_device *dev)
 				   ILK_FBCQ_DIS);
 			I915_WRITE(ILK_DISPLAY_CHICKEN2,
 				   I915_READ(ILK_DISPLAY_CHICKEN2) |
-				   ILK_DPARB_GATE);
+				   ILK_DPARB_GATE | ILK_ELPIN_409_SELECT);
 			I915_WRITE(ILK_DSPCLK_GATE,
 				   I915_READ(ILK_DSPCLK_GATE) |
 				   ILK_DPFC_DIS1 |
@@ -6460,10 +6460,6 @@ void intel_enable_clock_gating(struct drm_device *dev)
 				   ILK_CLK_FBC);
 		}
 
-		I915_WRITE(ILK_DISPLAY_CHICKEN2,
-			   I915_READ(ILK_DISPLAY_CHICKEN2) |
-			   ILK_ELPIN_409_SELECT);
-
 		if (IS_GEN5(dev)) {
 			I915_WRITE(_3D_CHICKEN2,
 				   _3D_CHICKEN2_WM_READ_PIPELINED << 16 |
@@ -6484,16 +6480,21 @@ void intel_enable_clock_gating(struct drm_device *dev)
 			 * The bit14 of 0x70180
 			 * The bit14 of 0x71180
 			 */
-			I915_WRITE(ILK_DISPLAY_CHICKEN1,
-				   I915_READ(ILK_DISPLAY_CHICKEN1) |
-				   ILK_FBCQ_DIS | ILK_PABSTRETCH_DIS);
+			if (I915_HAS_FBC(dev) && i915_powersave) {
+				I915_WRITE(ILK_DISPLAY_CHICKEN1,
+					   I915_READ(ILK_DISPLAY_CHICKEN1) |
+					   ILK_FBCQ_DIS | ILK_PABSTRETCH_DIS);
+				I915_WRITE(ILK_DSPCLK_GATE,
+					   I915_READ(ILK_DSPCLK_GATE) |
+					   ILK_DPFC_CLK_GATE | ILK_DPFCR_CLK_GATE);
+			} else
+				I915_WRITE(ILK_DISPLAY_CHICKEN1,
+					   I915_READ(ILK_DISPLAY_CHICKEN1) |
+					   ILK_PABSTRETCH_DIS);
+
 			I915_WRITE(ILK_DISPLAY_CHICKEN2,
 				   I915_READ(ILK_DISPLAY_CHICKEN2) |
-				   ILK_DPARB_GATE | ILK_VSDPFD_FULL);
-			I915_WRITE(ILK_DSPCLK_GATE,
-				   I915_READ(ILK_DSPCLK_GATE) |
-				   ILK_DPARB_CLK_GATE  |
-				   ILK_DPFD_CLK_GATE);
+				   ILK_VSDPFD_FULL | ILK_ELPIN_409_SELECT);
 
 			I915_WRITE(DSPACNTR,
 				   I915_READ(DSPACNTR) |
-- 
1.7.4.1