Having transitioned to using PIPECONTROL to combine the flush with the breadcrumb write using their post-sync functions, assume that this will resolve the serialisation with the subsequent MI_USER_INTERRUPT. That is when inspecting the breadcrumb after an interrupt we can rely on the write being posted (i.e. the HWSP will be coherent). Testing using gem_sync shows that the PIPECONTROL + CS stall does serialise the command streamer sufficient that the breadcrumb lands before the MI_USER_INTERRUPT. The same is not true for MI_FLUSH_DW. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_ringbuffer.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index d773f7dd32a9..1b9264883a8d 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2218,13 +2218,11 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine) engine->emit_flush = gen7_render_ring_flush; engine->emit_breadcrumb = gen7_rcs_emit_breadcrumb; engine->emit_breadcrumb_sz = gen7_rcs_emit_breadcrumb_sz; - engine->irq_seqno_barrier = gen6_seqno_barrier; } else if (IS_GEN(dev_priv, 6)) { engine->init_context = intel_rcs_ctx_init; engine->emit_flush = gen6_render_ring_flush; engine->emit_breadcrumb = gen6_rcs_emit_breadcrumb; engine->emit_breadcrumb_sz = gen6_rcs_emit_breadcrumb_sz; - engine->irq_seqno_barrier = gen6_seqno_barrier; } else if (IS_GEN(dev_priv, 5)) { engine->emit_flush = gen4_render_ring_flush; } else { -- 2.20.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx