Commits
Chris Wilson committed f7770bfd9fd
drm/i915: Skip clearing the GGTT on full-ppgtt systems Under full-ppgtt, access to the global GTT is carefully regulated through hardware functions (i.e. userspace cannot read and write to arbitrary locations in the GGTT via the GPU). With this restriction in place, we can forgo clearing stale entries from the GGTT as they will not be accessed. For aliasing-ppgtt, we could almost do the same except that we do allow userspace access to the global-GTT via execbuf in order to workraound some quirks of certain instructions. (This execbuf path is filtered out with EINVAL on full-ppgtt.) The most dramatic effect this will have will be during resume, as with full-ppgtt the GGTT is only used sparingly. References: https://bugs.freedesktop.org/show_bug.cgi?id=94722 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Weinehall <david.weinehall@intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Tested-by: David Weinehall <david.weinehall@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1463207195-22076-4-git-send-email-chris@chris-wilson.co.uk