Commit ed4a5184 authored by Linus Torvalds's avatar Linus Torvalds

Revert "drm/i915: fix infinite recursion on unbind due to ilk vt-d w/a"

This reverts commit eb1711bb.

It blows up the i915 seqno tracking, resulting in the

	BUG_ON(seqno == 0);

in i915_wait_request() triggering, which will cause lock-ups.

See for example
  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/903010
  https://lkml.org/lkml/2011/12/14/395Reported-requested-and-tested-by: default avatarDirk Hohndel <dirk@hohndel.org>
Reported-by: default avatarRichard Eames <Richard.Eames@flinders.edu.au>
Reported-by: default avatarRocko Requin <rockorequin@hotmail.com>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 64b3dcc3
...@@ -2026,13 +2026,8 @@ i915_wait_request(struct intel_ring_buffer *ring, ...@@ -2026,13 +2026,8 @@ i915_wait_request(struct intel_ring_buffer *ring,
* to handle this, the waiter on a request often wants an associated * to handle this, the waiter on a request often wants an associated
* buffer to have made it to the inactive list, and we would need * buffer to have made it to the inactive list, and we would need
* a separate wait queue to handle that. * a separate wait queue to handle that.
*
* To avoid a recursion with the ilk VT-d workaround (that calls
* gpu_idle when unbinding objects with interruptible==false) don't
* retire requests in that case (because it might call unbind if the
* active list holds the last reference to the object).
*/ */
if (ret == 0 && dev_priv->mm.interruptible) if (ret == 0)
i915_gem_retire_requests_ring(ring); i915_gem_retire_requests_ring(ring);
return ret; return ret;
......
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