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.
v2: add fixes tag and cc stable kernel (zhenyu wang) 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 --- 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 f4c992d96087..88ed2e9df253 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c @@ -1946,7 +1946,7 @@ 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); }
/**