[PATCH v2 1/2] drm/amdgpu: Fix a bug on flag table_freed

[Eric Huang]

table_freed will be always true when mapping a memory with size
bigger than 2MB. The problem is page table's entries are always
existed, but existing mapping depends on page talbe's bo, so
using a check of page table's bo existed will resolve the issue.

Signed-off-by: Eric Huang <jinhuieric.huang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 539c117906cc..2c20bba7dc1a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1582,9 +1582,12 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 			 * completely covered by the range and so potentially still in use.
 			 */
 			while (cursor.pfn < frag_start) {
-				amdgpu_vm_free_pts(adev, params->vm, &cursor);
+				/* Make sure previous mapping is freed */
+				if (cursor.entry->base.bo) {
+					params->table_freed = true;
+					amdgpu_vm_free_pts(adev, params->vm, &cursor);
+				}
 				amdgpu_vm_pt_next(adev, &cursor);
-				params->table_freed = true;
 			}
 
 		} else if (frag >= shift) {
-- 
2.25.1