On Fri, Dec 12, 2014 at 11:09:15AM +0200, Ville Syrjälä wrote: > On Thu, Dec 11, 2014 at 08:17:00AM +0000, Chris Wilson wrote: > > In order to act as a full command barrier by itself, we need to tell the > > pipecontrol to actually stall the command streamer while the flush runs. > > We require the full command barrier before operations like > > MI_SET_CONTEXT, which currently rely on a prior invalidate flush. > > > > References: https://bugs.freedesktop.org/show_bug.cgi?id=83677 > > Cc: Simon Farnsworth <simon@xxxxxxxxxxxx> > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > --- > > drivers/gpu/drm/i915/intel_ringbuffer.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c > > index 282279b83ca4..02fb478a2867 100644 > > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c > > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c > > @@ -380,6 +380,8 @@ gen7_render_ring_flush(struct intel_engine_cs *ring, > > flags |= PIPE_CONTROL_QW_WRITE; > > flags |= PIPE_CONTROL_GLOBAL_GTT_IVB; > > > > + flags |= PIPE_CONTROL_STALL_AT_SCOREBOARD; > > + > > Hmm. BSpec says that the render cache won't be flushed when this bit > is set. Is that going to cause problems for the gpu_cache_dirty cases > where seem to do invalidate+flush with a single PIPE_CONTROL? I thought it was DEPTH_STALL that disabled the write flush. It is redundant in the case where the write flush is taking place though and you can do: /* bspec is not entirely clear when the render target cache flush is * disabled with other stall bits set, so don't set any additional * stalls if we are already using the cache flush. */ if ((flags & PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH) == 0) flags |= PIPE_CONTROL_STALL_AT_SCOREBOARD; -Chris -- Chris Wilson, Intel Open Source Technology Centre -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html