PCI quirk: TI XIO200a erroneously reports support for fast b2b transfers
Gabe Black [Tue, 6 Oct 2009 14:19:45 +0000 (09:19 -0500)]
This quirk will disable fast back to back transfer on the secondary bus
segment of the TI Bridge.

Signed-off-by: Gabe Black <gabe.black@ni.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/quirks.c
include/linux/pci_ids.h

index 6099fac..efa6534 100644 (file)
@@ -670,6 +670,25 @@ static void __devinit quirk_vt8235_acpi(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA,    PCI_DEVICE_ID_VIA_8235, quirk_vt8235_acpi);
 
+/*
+ * TI XIO2000a PCIe-PCI Bridge erroneously reports it supports fast back-to-back:
+ *     Disable fast back-to-back on the secondary bus segment
+ */
+static void __devinit quirk_xio2000a(struct pci_dev *dev)
+{
+       struct pci_dev *pdev;
+       u16 command;
+
+       dev_warn(&dev->dev, "TI XIO2000a quirk detected; "
+               "secondary bus fast back-to-back transfers disabled\n");
+       list_for_each_entry(pdev, &dev->subordinate->devices, bus_list) {
+               pci_read_config_word(pdev, PCI_COMMAND, &command);
+               if (command & PCI_COMMAND_FAST_BACK)
+                       pci_write_config_word(pdev, PCI_COMMAND, command & ~PCI_COMMAND_FAST_BACK);
+       }
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_XIO2000A,
+                       quirk_xio2000a);
 
 #ifdef CONFIG_X86_IO_APIC 
 
index da1fda8..f490e7a 100644 (file)
 #define PCI_DEVICE_ID_TI_X515          0x8036
 #define PCI_DEVICE_ID_TI_XX12          0x8039
 #define PCI_DEVICE_ID_TI_XX12_FM       0x803b
+#define PCI_DEVICE_ID_TI_XIO2000A      0x8231
 #define PCI_DEVICE_ID_TI_1130          0xac12
 #define PCI_DEVICE_ID_TI_1031          0xac13
 #define PCI_DEVICE_ID_TI_1131          0xac15