[PATCH 24/27] drm/i915/gen9: Add WaFbcTurnOffFbcWatermark

Mika Kuoppala
2016-06-07T14:23:39Z

According to bspec this prevents screen corruption when fbc is
used.

v2: This workaround has a name, use it (Ville)
v3: remove bogus gen check on ilk/vlv wm path (Ville)

References: HSD#2135555, HSD#2137270, BSID#562
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_pm.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index d766d1a562df..de3dd241e151 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -69,6 +69,10 @@ static void gen9_init_clock_gating(struct drm_device *dev)
/* WaEnableChickenDCPR:skl,bxt,kbl */
I915_WRITE(GEN8_CHICKEN_DCPR_1,
I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
+
+ /* WaFbcTurnOffFbcWatermark:skl,bxt,kbl */
+ I915_WRITE(DISP_ARB_CTL,
+ I915_READ(DISP_ARB_CTL) | DISP_FBC_WM_DIS);
}

static void bxt_init_clock_gating(struct drm_device *dev)