diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel/svm.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index a3f84f2ff1ba..0c228787704f 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -789,7 +789,19 @@ prq_retry: goto prq_retry; } + /* + * A work in IO page fault workqueue may try to lock pasid_mutex now. + * Holding pasid_mutex while waiting in iopf_queue_flush_dev() for + * all works in the workqueue to finish may cause deadlock. + * + * It's unnecessary to hold pasid_mutex in iopf_queue_flush_dev(). + * Unlock it to allow the works to be handled while waiting for + * them to finish. + */ + lockdep_assert_held(&pasid_mutex); + mutex_unlock(&pasid_mutex); iopf_queue_flush_dev(dev); + mutex_lock(&pasid_mutex); /* * Perform steps described in VT-d spec CH7.10 to drain page |