On ke, 2017-05-31 at 20:05 +0100, Chris Wilson wrote:
> Commit 7c3f86b6dc51 ("drm/i915: Invalidate the guc ggtt TLB upon
> insertion") added the restoration of the invalidation routine after the
> GuC was disabled, but missed that the GuC was unconditionally disabled
> when not used. This then overwrites the invalidate routine for the older
> chipsets, causing havoc and breaking resume as the most obvious victim.
>
> We place the guard inside i915_ggtt_disable_guc() to be backport
> friendly (the bug was introduced into v4.11) but it would be preferred
> to be in more control over when this was guard (i.e. do not try and
> teardown the data structures before we have enabled them). That should
> be true with the reorganisation of the guc loaders.
>
> Reported-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Fixes: 7c3f86b6dc51 ("drm/i915: Invalidate the guc ggtt TLB upon insertion")
> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> Cc: Oscar Mateo <oscar.mateo@xxxxxxxxx>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
> Cc: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
> Cc: Arkadiusz Hiler <arkadiusz.hiler@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.11+
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Regards, Joonas
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation