In order to avoid some nasty mutex inversions, commit
09c5ab384f6f
("drm/i915: Keep rings pinned while the context is active") allowed the
intel_ring unpinning to be run concurrently with the next context
pinning it. Thus each step in intel_ring_unpin() needed to be atomic and
ordered in a nice onion with intel_ring_pin() so that the lifetimes
overlapped and were always safe.
Sadly, a few steps in intel_ring_unpin() were overlooked, such as
closing the read/write pointers of the ring and discarding the
intel_ring.vaddr, as these steps were not serialised with
intel_ring_pin() and so could leave the ring in disarray.
Fixes:
09c5ab384f6f ("drm/i915: Keep rings pinned while the context is active")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191118230254.2615942-6-chris@chris-wilson.co.uk
(cherry picked from commit
a266bf42006004306dd48a9082c35dfbff153307)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
i915_vma_make_unshrinkable(vma);
- GEM_BUG_ON(ring->vaddr);
- ring->vaddr = addr;
+ /* Discard any unused bytes beyond that submitted to hw. */
+ intel_ring_reset(ring, ring->emit);
+ ring->vaddr = addr;
return 0;
err_ring:
if (!atomic_dec_and_test(&ring->pin_count))
return;
- /* Discard any unused bytes beyond that submitted to hw. */
- intel_ring_reset(ring, ring->emit);
-
i915_vma_unset_ggtt_write(vma);
if (i915_vma_is_map_and_fenceable(vma))
i915_vma_unpin_iomap(vma);
else
i915_gem_object_unpin_map(vma->obj);
- GEM_BUG_ON(!ring->vaddr);
- ring->vaddr = NULL;
-
- i915_vma_unpin(vma);
i915_vma_make_purgeable(vma);
+ i915_vma_unpin(vma);
}
static struct i915_vma *create_ring_vma(struct i915_ggtt *ggtt, int size)