Userptr causes lockdep to complain when we are using the aliasing-ppgtt (and ggtt, but for that it is rightfully so to complain about) in that when we revoke the userptr we take a mutex which we also use to revoke the mmaps. However, we only revoke mmaps for GGTT bindings and we never allow userptr to create a GGTT binding so the warning should be false and is simply caused by our conflation of the aliasing-ppgtt with the ggtt. So lets try treating the binding into the aliasing-ppgtt as a separate lockclass from the ggtt. The downside is that we are deliberately suppressing lockdep;s ability to warn us of cycles.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/478 --- drivers/gpu/drm/i915/i915_vma.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index 191577a98390..9f4a31cd54ac 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -914,7 +914,8 @@ int i915_vma_pin(struct i915_vma *vma, u64 size, u64 alignment, u64 flags) wakeref = intel_runtime_pm_get(&vma->vm->i915->runtime_pm); /* No more allocations allowed once we hold vm->mutex */ - err = mutex_lock_interruptible(&vma->vm->mutex); + err = mutex_lock_interruptible_nested(&vma->vm->mutex, + !(flags & PIN_GLOBAL)); if (err) goto err_fence; @@ -1320,7 +1321,7 @@ int i915_vma_unbind(struct i915_vma *vma) if (err) goto out_rpm; - err = mutex_lock_interruptible(&vm->mutex); + err = mutex_lock_interruptible_nested(&vma->vm->mutex, !wakeref); if (err) goto out_rpm; -- 2.20.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
