Only assert that the i915_vma is now idle if and only if no other pins
are present. If another user has the i915_vma pinned, they may submit
more work to the i915_vma skipping the vm->mutex used to serialise the
unbind. We need to wait again, if we want to continue and unbind this
vma.
However, if we own the i915_vma (we hold the vm->mutex for the unbind
and the pin_count is 0), we can assert that the vma remains idle as we
unbind.
Fixes: 2850748ef876 ("drm/i915: Pull i915_vma_pin under the vm->mutex")
Closes: https://gitlab.freedesktop.org/drm/intel/issues/530
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20200123224459.38128-1-chris@xxxxxxxxxxxxxxxxxx
(cherry picked from commit 60e94557fff1f5514c7fc4da7ddc2c7a13ffff26)
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
(cherry picked from commit e4edd4fcbf4daf9d4319bef0bfaf350cb672239a)
---
drivers/gpu/drm/i915/i915_vma.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 01c822256b39..7c7e152cc5ff 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -1149,16 +1149,26 @@ int __i915_vma_unbind(struct i915_vma *vma)
if (ret)
return ret;
- GEM_BUG_ON(i915_vma_is_active(vma));
if (i915_vma_is_pinned(vma)) {
vma_print_allocator(vma, "is pinned");
return -EBUSY;
}
- GEM_BUG_ON(i915_vma_is_active(vma));
+ /*
+ * After confirming that no one else is pinning this vma, wait for
+ * any laggards who may have crept in during the wait (through
+ * a residual pin skipping the vm->mutex) to complete.
+ */
+ ret = i915_vma_sync(vma);
+ if (ret)
+ return ret;
+
if (!drm_mm_node_allocated(&vma->node))
return 0;
+ GEM_BUG_ON(i915_vma_is_pinned(vma));
+ GEM_BUG_ON(i915_vma_is_active(vma));
+
if (i915_vma_is_map_and_fenceable(vma)) {
/*
* Check that we have flushed all writes through the GGTT
--
2.25.1
