On Mon, Nov 28, 2011 at 10:24:55PM +0100, Daniel Vetter wrote: > On Sanybridge a few MI read/write commands only work when ppgtt is > enabled. Userspace therefore needs to be able to check whether ppgtt > is enabled. For added hilarity, you need to reset the "use global GTT" > bit on both snb/ivb when ppgtt is enabled, otherwise it won't work. > Despite what bspec says about automatically using ppgtt ... > > Luckily PIPE_CONTROL (the only write cmd current userspace uses) is > not affected by all this, as tested by tests/gem_pipe_control_store_loop. Since this is all SNB only, and we have no good benchmarks to show performance gains, can we not just enable this for IVB+? > > Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
