drm/i915: Turn on a required 3D clock gating bit on Sandybridge.

Fixes rendering failures in Unigine Tropics and Sanctuary and the mesa
"fire" demo.

Signed-off-by: Eric Anholt <eric@anholt.net>
Cc: stable@kernel.org
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 5a09416e611f..b807275ea739 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3444,6 +3444,9 @@
 #define  GT_FIFO_FREE_ENTRIES                   0x120008
 #define    GT_FIFO_NUM_RESERVED_ENTRIES         20
 
+#define GEN6_UCGCTL2                            0x9404
+# define GEN6_RCPBUNIT_CLOCK_GATE_DISABLE               (1 << 12)
+
 #define GEN6_RPNSWREQ                           0xA008
 #define   GEN6_TURBO_DISABLE                    (1<<31)
 #define   GEN6_FREQUENCY(x)                     ((x)<<25)