Merge tag 'drm-intel-next-fixes-2016-05-25' of git://anongit.freedesktop.org/drm...

[cascardo/linux.git] / drivers / gpu / drm / i915 / intel_pm.c

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f3875bd..a7ef45d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6740,6 +6740,12 @@ static void broadwell_init_clock_gating(struct drm_device *dev)
        misccpctl = I915_READ(GEN7_MISCCPCTL);
        I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
        I915_WRITE(GEN8_L3SQCREG1, BDW_WA_L3SQCREG1_DEFAULT);
+       /*
+        * Wait at least 100 clocks before re-enabling clock gating. See
+        * the definition of L3SQCREG1 in BSpec.
+        */
+       POSTING_READ(GEN8_L3SQCREG1);
+       udelay(1);
        I915_WRITE(GEN7_MISCCPCTL, misccpctl);
 
        /*