[ 42/68] drm/i915: gen7: work around a system hang on IVB

From: Greg KH
Date: Fri Mar 09 2012 - 14:53:28 EST


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

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

From: Eugeni Dodonov <eugeni.dodonov@xxxxxxxxx>

commit db099c8f963fe656108e0a068274c5580a17f69b upstream.

This adds the workaround for WaCatErrorRejectionIssue which could result
in a system hang.

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>
Reviewed-by: Kenneth Graunke <kenneth@xxxxxxxxxxxxx>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@xxxxxxxxx>
Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/i915/i915_reg.h | 4 ++++
drivers/gpu/drm/i915/intel_display.c | 5 +++++
2 files changed, 9 insertions(+)

--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2854,6 +2854,10 @@
#define GEN7_L3_CHICKEN_MODE_REGISTER 0xB030
#define GEN7_WA_L3_CHICKEN_MODE 0x20000000

+/* WaCatErrorRejectionIssue */
+#define GEN7_SQ_CHICKEN_MBCUNIT_CONFIG 0x9030
+#define GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB (1<<11)
+
/* PCH */

/* south display engine interrupt */
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7470,6 +7470,11 @@ static void ivybridge_init_clock_gating(
I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER,
GEN7_WA_L3_CHICKEN_MODE);

+ /* This is required by WaCatErrorRejectionIssue */
+ I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
+ I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
+ GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);
+
for_each_pipe(pipe)
I915_WRITE(DSPCNTR(pipe),
I915_READ(DSPCNTR(pipe)) |


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