From 9ca1d10d748e56964de95e3ed80211b192f56cf4 Mon Sep 17 00:00:00 2001 From: Eric Anholt <eric@anholt.net> Date: Mon, 7 Nov 2011 16:07:05 -0800 Subject: [PATCH] drm/i915: Turn on another required clock gating bit on gen6. Unlike the previous one, I don't have known testcases it fixes. I'd rather not go through the same debug cycle on whatever testcases those might be. Signed-off-by: Eric Anholt <eric@anholt.net> Cc: stable@kernel.org Signed-off-by: Keith Packard <keithp@keithp.com> --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_display.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index b807275ea739..a34e86630f26 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3446,6 +3446,7 @@ #define GEN6_UCGCTL2 0x9404 # define GEN6_RCPBUNIT_CLOCK_GATE_DISABLE (1 << 12) +# define GEN6_RCCUNIT_CLOCK_GATE_DISABLE (1 << 11) #define GEN6_RPNSWREQ 0xA008 #define GEN6_TURBO_DISABLE (1<<31) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 2b2a7645cd0c..591eb0ed3110 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8154,8 +8154,13 @@ static void gen6_init_clock_gating(struct drm_device *dev) * some amount of runtime in the Mesa "fire" demo, and Unigine * Sanctuary and Tropics, and apparently anything else with * alpha test or pixel discard. + * + * According to the spec, bit 11 (RCCUNIT) must also be set, + * but we didn't debug actual testcases to find it out. */ - I915_WRITE(GEN6_UCGCTL2, GEN6_RCPBUNIT_CLOCK_GATE_DISABLE); + I915_WRITE(GEN6_UCGCTL2, + GEN6_RCPBUNIT_CLOCK_GATE_DISABLE | + GEN6_RCCUNIT_CLOCK_GATE_DISABLE); /* * According to the spec the following bits should be -- 2.20.1