[PATCH 1/1] drm/amdgpu: fix the memleak caused by fence not released

[Le Ma <le.ma@amd.com>]

On systems with CONFIG_SLUB_DEBUG enabled, the memleak like below
will show up explicitly during driver unloading if created bo without
drm_timeline object before.

    BUG drm_sched_fence (Tainted: G           OE     ): Objects remaining in drm_sched_fence on __kmem_cache_shutdown()
    -----------------------------------------------------------------------------
    Call Trace:
    <TASK>
    dump_stack_lvl+0x4c/0x70
    dump_stack+0x14/0x20
    slab_err+0xb0/0xf0
    ? srso_alias_return_thunk+0x5/0xfbef5
    ? flush_work+0x12/0x20
    ? srso_alias_return_thunk+0x5/0xfbef5
    __kmem_cache_shutdown+0x163/0x2e0
    kmem_cache_destroy+0x61/0x170
    drm_sched_fence_slab_fini+0x19/0x900

Thus call dma_fence_put properly to avoid the memleak.

Signed-off-by: Le Ma <le.ma@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 8b67aae6c2fe..ad3c5fdf6970 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -125,8 +125,11 @@ amdgpu_gem_update_bo_mapping(struct drm_file *filp,
 	struct amdgpu_vm *vm = &fpriv->vm;
 	struct dma_fence *last_update;
 
-	if (!syncobj)
+	if (!syncobj) {
+		dma_fence_wait(fence, false);
+		dma_fence_put(fence);
 		return;
+	}
 
 	/* Find the last update fence */
 	switch (operation) {
-- 
2.43.2