[Intel-gfx] [PATCH] drm/i915: disable LVDS clock gating on CPT

[Jesse Barnes]

Needed to prevent display corruption in high res panels.

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_reg.h |    2 ++
 drivers/gpu/drm/i915/intel_pm.c |    4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 96fd2ce..cca670a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4338,7 +4338,9 @@
 #define FDI_RX_CHICKEN(pipe) _PIPE(pipe, _FDI_RXA_CHICKEN, _FDI_RXB_CHICKEN)
 
 #define SOUTH_DSPCLK_GATE_D	0xc2020
+#define  PCH_LVDSUNIT_CLOCK_GATE_DISABLE (1<<30)
 #define  PCH_DPLSUNIT_CLOCK_GATE_DISABLE (1<<29)
+#define  PCH_LVDSUNIT2_CLOCK_GATE_DISABLE (1<<14)
 #define  PCH_LP_PARTITION_LEVEL_DISABLE  (1<<12)
 
 /* CPU: FDI_TX */
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 698257c..f6765e0 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4791,7 +4791,9 @@ static void cpt_init_clock_gating(struct drm_device *dev)
 	 * gating for the panel power sequencer or it will fail to
 	 * start up when no ports are active.
 	 */
-	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
+	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE |
+		   PCH_LVDSUNIT_CLOCK_GATE_DISABLE |
+		   PCH_LVDSUNIT2_CLOCK_GATE_DISABLE);
 	I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) |
 		   DPLS_EDP_PPS_FIX_DIS);
 	/* The below fixes the weird display corruption, a few pixels shifted
-- 
1.7.9.5