[ Upstream commit 663a50ceac75c2208d2ad95365bc8382fd42f44d ]
shadow mm's pin count got increased in workload preparation phase, which
is after workload scanning.
it will get decreased in complete_current_workload() anyway after
workload completion.
Sometimes, if a workload meets a scanning error, its shadow mm pin count
will not get increased but will get decreased in the end.
This patch lets shadow mm's pin count not go below 0.
Fixes: 2707e4446688 ("drm/i915/gvt: vGPU graphics memory virtualization")
Cc: zhen...@linux.intel.com
Cc: sta...@vger.kernel.org #4.14+
Signed-off-by: Yan Zhao <yan.y.z...@intel.com>
Signed-off-by: Zhenyu Wang <zhen...@linux.intel.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
drivers/gpu/drm/i915/gvt/gtt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 00aad8164dec..542f31ce108f 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1940,7 +1940,7 @@ void _intel_vgpu_mm_release(struct kref *mm_ref)
*/
void intel_vgpu_unpin_mm(struct intel_vgpu_mm *mm)
{
- atomic_dec(&mm->pincount);
+ atomic_dec_if_positive(&mm->pincount);
}
/**
--
2.19.1
