[ 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: zhenyuw@linux.intel.com
Cc: stable@vger.kernel.org #4.14+
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
if (WARN_ON(mm->type != INTEL_GVT_MM_PPGTT))
return;
- atomic_dec(&mm->pincount);
+ atomic_dec_if_positive(&mm->pincount);
}
/**