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 <chris@xxxxxxxxxxxxxxxxxx> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- 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 b/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 *req) 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, I915_DISPATCH_SECURE); -- 2.13.3