[PATCH v4 3/6] drm/i915/gen8: Add WaDisableCtxRestoreArbitration workaround

Arun Siluvery
2015-06-16T19:25:33Z

In Indirect and Per context w/a batch buffer,
+WaDisableCtxRestoreArbitration

Signed-off-by: Rafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
---
drivers/gpu/drm/i915/intel_lrc.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index dcc3f2e..c9875f6 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1091,10 +1091,11 @@ static int gen8_init_indirectctx_bb(struct intel_engine_cs *ring,

index = offset;

- /* FIXME: fill one cacheline with NOOPs.
- * Replace these instructions with WA
- */
- while (index < (offset + 16))
+ /* WaDisableCtxRestoreArbitration:bdw,chv */
+ cmd[index++] = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+
+ /* padding */
+ while (((unsigned long) (cmd + index) % CACHELINE_BYTES) != 0)
cmd[index++] = MI_NOOP;

/*
@@ -1126,13 +1127,10 @@ static int gen8_init_perctx_bb(struct intel_engine_cs *ring,

index = offset;

- /* FIXME: fill one cacheline with NOOPs.
- * Replace these instructions with WA
- */
- while (index < (offset + 16))
- cmd[index++] = MI_NOOP;
+ /* WaDisableCtxRestoreArbitration:bdw,chv */
+ cmd[index++] = MI_ARB_ON_OFF | MI_ARB_ENABLE;

- cmd[index - 1] = MI_BATCH_BUFFER_END;
+ cmd[index++] = MI_BATCH_BUFFER_END;

kunmap_atomic(cmd);

--
2.3.0