From: Han, Weidong <weidong.han@intel.com>
Date: Sat, 4 Apr 2009 09:21:26 +0000 (+0800)
Subject: x86, dmar: check if it's initialized before disable queue invalidation
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=34aaaa948e3c9dd65b27fa499c5c9e8d8f1227cf;p=linux-beck.git

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 ef25caade54b..472be1c3fff0 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -523,6 +523,13 @@ int __init enable_intr_remapping(int eim)
 	for_each_drhd_unit(drhd) {
 		struct intel_iommu *iommu = drhd->iommu;
 
+		/*
+		 * If the queued invalidation is already initialized,
+		 * shouldn't disable it.
+		 */
+		if (iommu->qi)
+			continue;
+
 		/*
 		 * Clear previous faults.
 		 */