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Diffstat (limited to 'arch/x86_64/kernel/pci-dma.c')
-rw-r--r--arch/x86_64/kernel/pci-dma.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 651ccfb0669..90f6315d02d 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -22,8 +22,7 @@ EXPORT_SYMBOL(bad_dma_address);
int iommu_bio_merge __read_mostly = 0;
EXPORT_SYMBOL(iommu_bio_merge);
-int iommu_sac_force __read_mostly = 0;
-EXPORT_SYMBOL(iommu_sac_force);
+static int iommu_sac_force __read_mostly = 0;
int no_iommu __read_mostly;
#ifdef CONFIG_IOMMU_DEBUG
@@ -322,5 +321,17 @@ static int __init pci_iommu_init(void)
return 0;
}
+#ifdef CONFIG_PCI
+/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
+
+static __devinit void via_no_dac(struct pci_dev *dev)
+{
+ if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && forbid_dac == 0) {
+ printk(KERN_INFO "PCI: VIA PCI bridge detected. Disabling DAC.\n");
+ forbid_dac = 1;
+ }
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac);
+#endif
/* Must execute after PCI subsystem */
fs_initcall(pci_iommu_init);