diff options
| -rw-r--r-- | drivers/pci/quirks.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 53ee09a592b..ce35a8f956f 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1611,6 +1611,34 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_CK804_PCIE, DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_CK804_PCIE, quirk_nvidia_ck804_pcie_aer_ext_cap); +static void __devinit quirk_via_cx700_pci_parking_caching(struct pci_dev *dev) +{ + /* + * Disable PCI Bus Parking and PCI Master read caching on CX700 + * which causes unspecified timing errors with a VT6212L on the PCI + * bus leading to USB2.0 packet loss. The defaults are that these + * features are turned off but some BIOSes turn them on. + */ + + uint8_t b; + if (pci_read_config_byte(dev, 0x76, &b) == 0) { + if (b & 0x40) { + /* Turn off PCI Bus Parking */ + pci_write_config_byte(dev, 0x76, b ^ 0x40); + + /* Turn off PCI Master read caching */ + pci_write_config_byte(dev, 0x72, 0x0); + pci_write_config_byte(dev, 0x75, 0x1); + pci_write_config_byte(dev, 0x77, 0x0); + + printk(KERN_INFO + "PCI: VIA CX700 PCI parking/caching fixup on %s\n", + pci_name(dev)); + } + } +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_VIA, 0x324e, quirk_via_cx700_pci_parking_caching); + #ifdef CONFIG_PCI_MSI /* Some chipsets do not support MSI. We cannot easily rely on setting * PCI_BUS_FLAGS_NO_MSI in its bus flags because there are actually |