• Daniel Vetter's avatar
    drm/i915: add HAS_ALIASING_PPGTT parameter for userspace · 777ee96f
    Daniel Vetter authored
    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 snb 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.
    Reviewed-and-tested-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
    Signed-Off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    777ee96f
i915_dma.c 59 KB