[PATCH] drm/amdgpu: fix VM leaf walking

[Christian König]

Make sure we don't try to go down further after the leave walk already
ended. This fixes a crash with a new VM test.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index db0cbf8d219d..352b30409060 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -542,7 +542,8 @@ static void amdgpu_vm_pt_next_leaf(struct amdgpu_device *adev,
 				   struct amdgpu_vm_pt_cursor *cursor)
 {
 	amdgpu_vm_pt_next(adev, cursor);
-	while (amdgpu_vm_pt_descendant(adev, cursor));
+	if (cursor->pfn != ~0ll)
+		while (amdgpu_vm_pt_descendant(adev, cursor));
 }
 
 /**
-- 
2.17.1