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>
This commit is contained in:
Eric Anholt 2011-11-07 16:07:04 -08:00 committed by Keith Packard
parent 680da876f4
commit 406478dc91
2 changed files with 12 additions and 0 deletions

View file

@ -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)

View file

@ -8148,6 +8148,15 @@ static void gen6_init_clock_gating(struct drm_device *dev)
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
/* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock
* gating disable must be set. Failure to set it results in
* flickering pixels due to Z write ordering failures after
* some amount of runtime in the Mesa "fire" demo, and Unigine
* Sanctuary and Tropics, and apparently anything else with
* alpha test or pixel discard.
*/
I915_WRITE(GEN6_UCGCTL2, GEN6_RCPBUNIT_CLOCK_GATE_DISABLE);
/*
* According to the spec the following bits should be
* set in order to enable memory self-refresh and fbc: