1 files changed, 5 insertions, 2 deletions

diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 9c44f4f2433d..4dcb671bd19f 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -236,6 +236,9 @@ __init int iommu_setup(char *p)
 {
     iommu_merge = 1;
 
+        if (!p)
+                return -EINVAL;
+
     while (*p) {
             if (!strncmp(p,"off",3))
                     no_iommu = 1;
@@ -278,9 +281,9 @@ __init int iommu_setup(char *p)
             if (*p == ',')
                     ++p;
     }
-    return 1;
+    return 0;
 }
-__setup("iommu=", iommu_setup);
+early_param("iommu", iommu_setup);
 
 void __init pci_iommu_alloc(void)
 {