From 3e9215796e22dd0d5f4c0f1d7d6851918d580c94 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <joerg.roedel@amd.com>
Date: Fri, 11 Jul 2008 17:14:27 +0200
Subject: [PATCH] --- yaml --- r: 104319 b: refs/heads/master c:
 136f78a19cf94d469f31a4009c7c0ac2301fbbf0 h: refs/heads/master i:   104317:
 3713013682cad6c2b2c1d2889b7c0336e4938b12   104315:
 80e3c04798cc3b850344b37c03ef5b8bd6a0d74a   104311:
 04642b0a03cbc8be961d81f9224439341cd95be2   104303:
 b5f43275cc2bdc61d0ff83835a308788673a38ed   104287:
 35bf520ea93d885a4b1273a156fda87f0ae02026   104255:
 540f138c0a2352d3abb3520ac2ba75086933fe9c   104191:
 48eb18563cd8036976572066f7d8429414f03158 v: v3

---
 [refs]                            |  2 +-
 trunk/arch/x86/kernel/amd_iommu.c | 10 +++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 9ecd8793058f..528932b2d6c8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9a836de0c9944c42d006ec241712c72e74737c73
+refs/heads/master: 136f78a19cf94d469f31a4009c7c0ac2301fbbf0
diff --git a/trunk/arch/x86/kernel/amd_iommu.c b/trunk/arch/x86/kernel/amd_iommu.c
index 9098f047c1a9..7fa2d5d57dd8 100644
--- a/trunk/arch/x86/kernel/amd_iommu.c
+++ b/trunk/arch/x86/kernel/amd_iommu.c
@@ -32,6 +32,8 @@
 #define to_pages(addr, size) \
 	 (round_up(((addr) & ~PAGE_MASK) + (size), PAGE_SIZE) >> PAGE_SHIFT)
 
+#define EXIT_LOOP_COUNT 10000000
+
 static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 
 /*
@@ -106,6 +108,7 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
 	struct command cmd;
 	volatile u64 ready = 0;
 	unsigned long ready_phys = virt_to_phys(&ready);
+	unsigned long i = 0;
 
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.data[0] = LOW_U32(ready_phys) | CMD_COMPL_WAIT_STORE_MASK;
@@ -120,8 +123,13 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
 	if (ret)
 		return ret;
 
-	while (!ready)
+	while (!ready && (i < EXIT_LOOP_COUNT)) {
+		++i;
 		cpu_relax();
+	}
+
+	if (unlikely((i == EXIT_LOOP_COUNT) && printk_ratelimit()))
+		printk(KERN_WARNING "AMD IOMMU: Completion wait loop failed\n");
 
 	return 0;
 }