[ 43/68] drm/i915: gen7: Disable the RHWO optimization as it can cause GPU hangs.

From: Greg KH
Date: Fri Mar 09 2012 - 14:53:22 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kenneth Graunke <kenneth@xxxxxxxxxxxxx>

commit d71de14ddf423ccc9a2e3f7e37553c99ead20d7c upstream.

The BSpec Workarounds page states that bits 10 and 26 must be set to
avoid 3D ring hangs.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41353
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44610
Tested-by: Eugeni Dodonov <eugeni.dodonov@xxxxxxxxx>
Signed-off-by: Kenneth Graunke <kenneth@xxxxxxxxxxxxx>
Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/i915/i915_reg.h | 3 +++
drivers/gpu/drm/i915/intel_display.c | 4 ++++
2 files changed, 7 insertions(+)

--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2848,6 +2848,9 @@
#define DISP_FBC_WM_DIS (1<<15)

/* GEN7 chicken */
+#define GEN7_COMMON_SLICE_CHICKEN1 0x7010
+# define GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC ((1<<10) | (1<<26))
+
#define GEN7_L3CNTLREG1 0xB01C
#define GEN7_WA_FOR_GEN7_L3_CONTROL 0x3C4FFF8C

--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7464,6 +7464,10 @@ static void ivybridge_init_clock_gating(

I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);

+ /* Apply the WaDisableRHWOOptimizationForRenderHang workaround. */
+ I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
+ GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);
+
/* WaApplyL3ControlAndL3ChickenMode requires those two on Ivy Bridge */
I915_WRITE(GEN7_L3CNTLREG1,
GEN7_WA_FOR_GEN7_L3_CONTROL);


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