[PATCH] drm/i915: disable LVDS clock gating on CPT v2

Jesse Barnes
2013-10-02T17:45:08Z

Needed to prevent display corruption in high res panels.

v2: use correct unit names (Rodrigo)

Signed-off-by: Jesse Barnes <jbarnes@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..b6312d9 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_DPLUNIT_CLOCK_GATE_DISABLE (1<<30)
#define PCH_DPLSUNIT_CLOCK_GATE_DISABLE (1<<29)
+#define PCH_CPUNIT_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..9443f8e 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_DPLUNIT_CLOCK_GATE_DISABLE |
+ PCH_CPUNIT_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