As we may have just bound the renderstate into the GGTT for execution, we
need to ensure that the GTT TLB are also flushed.

On snb-gt2, this would cause a random GPU hang at the start of a new
context (e.g. boot) and on snb-gt1, it was causing the renderstate batch
to take ~10s. It was the GPU hang that revealed the truth, as the CS
gleefully executed beyond the end of the golden renderstate batch, a good
indicator for a GTT TLB miss.

Signed-off-by: Chris Wilson <>
Cc: Mika Kuoppala <>
 drivers/gpu/drm/i915/i915_gem_render_state.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c 
index 241d827b85fb..3703dc91eeda 100644
--- a/drivers/gpu/drm/i915/i915_gem_render_state.c
+++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
@@ -242,6 +242,10 @@ int i915_gem_render_state_emit(struct drm_i915_gem_request 
                        goto err_unpin;
+       ret = req->engine->emit_flush(req, EMIT_INVALIDATE);
+       if (ret)
+               goto err_unpin;
        ret = req->engine->emit_bb_start(req,
                                         so->batch_offset, so->batch_size,

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