[PATCH 3.19.y-ckt 16/92] drm/radeon: fix lockup when BOs aren't part of the VM on release

[Kamal Mostafa]

3.19.8-ckt1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@xxxxxxx>

commit 26d4d129b6042197b4cbc8341c0618f99231af2f upstream.

If we unmap BOs before releasing them them the intervall tree locks
up because we try to remove an entry not inside the tree.

Based on a patch from Michel DÃnzer.

Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/radeon/radeon_vm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
index 2a5a4a9..16d8e95 100644
--- a/drivers/gpu/drm/radeon/radeon_vm.c
+++ b/drivers/gpu/drm/radeon/radeon_vm.c
@@ -1107,7 +1107,8 @@ void radeon_vm_bo_rmv(struct radeon_device *rdev,
 	list_del(&bo_va->bo_list);
 
 	mutex_lock(&vm->mutex);
-	interval_tree_remove(&bo_va->it, &vm->va);
+	if (bo_va->it.start || bo_va->it.last)
+		interval_tree_remove(&bo_va->it, &vm->va);
 	spin_lock(&vm->status_lock);
 	list_del(&bo_va->vm_status);
 
-- 
1.9.1

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