diff options
Diffstat (limited to 'arch/x86/kernel/pci-dma.c')
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 91443361cb67..48cccbe51aa5 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -1,12 +1,16 @@ #include <linux/dma-mapping.h> #include <linux/dmar.h> #include <linux/bootmem.h> +#include <linux/pci.h> #include <asm/proto.h> #include <asm/dma.h> #include <asm/gart.h> #include <asm/calgary.h> +int forbid_dac __read_mostly; +EXPORT_SYMBOL(forbid_dac); + const struct dma_mapping_ops *dma_ops; EXPORT_SYMBOL(dma_ops); @@ -121,3 +125,17 @@ void pci_iommu_shutdown(void) } /* Must execute after PCI subsystem */ fs_initcall(pci_iommu_init); + +#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 |