diff options
| -rw-r--r-- | drivers/pci/quirks.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 81d19d5683ac..8284958fc530 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1977,11 +1977,25 @@ 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. + * bus leading to USB2.0 packet loss. + * + * This quirk is only enabled if a second (on the external PCI bus) + * VT6212L is found -- the CX700 core itself also contains a USB + * host controller with the same PCI ID as the VT6212L. */ + /* Count VT6212L instances */ + struct pci_dev *p = pci_get_device(PCI_VENDOR_ID_VIA, + PCI_DEVICE_ID_VIA_8235_USB_2, NULL); uint8_t b; + + /* p should contain the first (internal) VT6212L -- see if we have + an external one by searching again */ + p = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235_USB_2, p); + if (!p) + return; + pci_dev_put(p); + if (pci_read_config_byte(dev, 0x76, &b) == 0) { if (b & 0x40) { /* Turn off PCI Bus Parking */ @@ -2008,7 +2022,7 @@ static void __devinit quirk_via_cx700_pci_parking_caching(struct pci_dev *dev) } } } -DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_VIA, 0x324e, quirk_via_cx700_pci_parking_caching); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, 0x324e, quirk_via_cx700_pci_parking_caching); /* * For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the |
