GEN6_RC6_THRESHOLD
I915_WRITE(GEN6_RC6_THRESHOLD, 37500); /* 37.5/125ms per EI */
I915_WRITE(GEN6_RC6_THRESHOLD, 625); /* 800us/1.28 for TO */
I915_WRITE(GEN6_RC6_THRESHOLD, 125000);
I915_WRITE(GEN6_RC6_THRESHOLD, 50000);
I915_WRITE(GEN6_RC6_THRESHOLD, 0x186);
I915_WRITE(GEN6_RC6_THRESHOLD, 0x557);