x86, dmar: check if it's initialized before disable queue invalidation
If queue invalidation is disabled after it's already initialized,
dmar_enable_qi won't re-enable it due to iommu->qi is allocated.
It may result in system hang when use queue invalidation. Add this
check to avoid this case.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index ef25caa..472be1c 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -524,6 +524,13 @@
struct intel_iommu *iommu = drhd->iommu;
/*
+ * If the queued invalidation is already initialized,
+ * shouldn't disable it.
+ */
+ if (iommu->qi)
+ continue;
+
+ /*
* Clear previous faults.
*/
dmar_fault(-1, iommu);