Commit 3cb115e6 authored Apr 08, 2019 by Yan Zhao Committed by Greg Kroah-Hartman Apr 17, 2019

drm/i915/gvt: do not let pin count of shadow mm go negative



[ 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: 2707e444 ("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>

parent 9b0cc293

drivers/gpu/drm/i915/gvt/gtt.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1629,7 +1629,7 @@ void intel_vgpu_unpin_mm(struct intel_vgpu_mm *mm)
		if (WARN_ON(mm->type != INTEL_GVT_MM_PPGTT))
		return;

		atomic_dec(&mm->pincount);
		atomic_dec_if_positive(&mm->pincount);
		}

		/**