[PATCH 3/5] drm/i915: WaInsertNoopAfterBatchEndCommand

Daniel Vetter
2012-10-18T09:32:06Z

Comment says that this applies to earlier gens, too. Since two more
MI_NOOP's can't hurt that much, I've figured I'll apply this w/a down
to gen2.

v2: Correct the ringbuffer dword count for gen3, spotted by Chris
Wilson.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 984a0c5..38092dc 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -969,7 +969,7 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
{
int ret;

- ret = intel_ring_begin(ring, 2);
+ ret = intel_ring_begin(ring, 4);
if (ret)
return ret;

@@ -978,6 +978,11 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
MI_BATCH_GTT |
MI_BATCH_NON_SECURE_I965);
intel_ring_emit(ring, offset);
+ /* WaInsertNoopAfterBatchEndCommand: Command says to do the same after
+ * the batchbuffer start command. Unclear whether really required on
+ * gen3, but better safe than sorry. */
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_emit(ring, MI_NOOP);
intel_ring_advance(ring);

return 0;
@@ -996,7 +1001,10 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
intel_ring_emit(ring, MI_BATCH_BUFFER);
intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
intel_ring_emit(ring, offset + len - 8);
- intel_ring_emit(ring, 0);
+ /* WaInsertNoopAfterBatchEndCommand: Command says to do the same after
+ * the batchbuffer start command. Unclear whether really required on
+ * gen2, but better safe than sorry. */
+ intel_ring_emit(ring, MI_NOOP);
intel_ring_advance(ring);

return 0;
@@ -1008,12 +1016,16 @@ i915_dispatch_execbuffer(struct intel_ring_buffer *ring,
{
int ret;

- ret = intel_ring_begin(ring, 2);
+ ret = intel_ring_begin(ring, 4);
if (ret)
return ret;

intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_GTT);
intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
+ /* WaInsertNoopAfterBatchEndCommand: Command says to do the same after
+ * the batchbuffer start command. */
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_emit(ring, MI_NOOP);
intel_ring_advance(ring);

return 0;
--
1.7.10.4