drm/i915: implement WADP0ClockGatingDisable

Found in Bspec vol4h South Display Engine Registers [CPT, PPT],
section "5.3.1  TRANS_CHICKEN_1—Transcoder Chicken Bits 1"

v2: Make it compile.

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e30d34b080693309f075ac5e9040b57bca698090..3674891902fe65829224cd84e1ff506afc9ff5cd 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3824,6 +3824,10 @@
 #define  TRANS_6BPC             (2<<5)
 #define  TRANS_12BPC            (3<<5)
 
+#define _TRANSA_CHICKEN1        0xf0060
+#define _TRANSB_CHICKEN1        0xf1060
+#define TRANS_CHICKEN1(pipe) _PIPE(pipe, _TRANSA_CHICKEN1, _TRANSB_CHICKEN1)
+#define  TRANS_CHICKEN1_DP0UNIT_GC_DISABLE     (1<<4)
 #define _TRANSA_CHICKEN2        0xf0064
 #define _TRANSB_CHICKEN2        0xf1064
 #define TRANS_CHICKEN2(pipe) _PIPE(pipe, _TRANSA_CHICKEN2, _TRANSB_CHICKEN2)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 596d97a68c683e2701530c47015e99df751b2f35..fe8178bb7705ef2986b8ddde92b164a9cd60d7d9 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3794,6 +3794,7 @@ static void ibx_init_clock_gating(struct drm_device *dev)
 static void cpt_init_clock_gating(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
+       int pipe;
 
        /*
         * On Ibex Peak and Cougar Point, we need to disable clock
@@ -3803,6 +3804,11 @@ static void cpt_init_clock_gating(struct drm_device *dev)
        I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) |
                   DPLS_EDP_PPS_FIX_DIS);
+       /* WADP0ClockGatingDisable */
+       for_each_pipe(pipe) {
+               I915_WRITE(TRANS_CHICKEN1(pipe),
+                          TRANS_CHICKEN1_DP0UNIT_GC_DISABLE);
+       }
 }
 
 void intel_init_clock_gating(struct drm_device *dev)