[PATCH] PCI: nVidia quirk to make AER PCI-E extended capability visible

The nVidia CK804 PCI-E chipset supports the AER extended capability
but sometimes fails to link it (with some BIOS or after a warm reboot).
It makes the AER cap invisible to pci_find_ext_capability().

The patch adds a quirk to set the missing bit that controls the
linking of the capability.
By the way, it removes the corresponding code in the myri10ge driver.
Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Loic Prylli <loic@myri.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/quirks.c

@@ -1499,6 +1499,25 @@ static void __devinit quirk_p64h2_1k_io(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	0x1460,		quirk_p64h2_1k_io);
 
+/* Under some circumstances, AER is not linked with extended capabilities.
+ * Force it to be linked by setting the corresponding control bit in the
+ * config space.
+ */
+static void __devinit quirk_nvidia_ck804_pcie_aer_ext_cap(struct pci_dev *dev)
+{
+	uint8_t b;
+	if (pci_read_config_byte(dev, 0xf41, &b) == 0) {
+		if (!(b & 0x20)) {
+			pci_write_config_byte(dev, 0xf41, b | 0x20);
+			printk(KERN_INFO
+			       "PCI: Linking AER extended capability on %s\n",
+			       pci_name(dev));
+		}
+	}
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA,  PCI_DEVICE_ID_NVIDIA_CK804_PCIE,
+			quirk_nvidia_ck804_pcie_aer_ext_cap);
+
 EXPORT_SYMBOL(pcie_mch_quirk);
 #ifdef CONFIG_HOTPLUG
 EXPORT_SYMBOL(pci_fixup_device);

include/linux/pci_ids.h

@@ -1023,6 +1023,7 @@
 #define PCI_DEVICE_ID_NVIDIA_NVENET_8		0x0056
 #define PCI_DEVICE_ID_NVIDIA_NVENET_9		0x0057
 #define PCI_DEVICE_ID_NVIDIA_CK804_AUDIO	0x0059
+#define PCI_DEVICE_ID_NVIDIA_CK804_PCIE		0x005d
 #define PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS	0x0064
 #define PCI_DEVICE_ID_NVIDIA_NFORCE2_IDE	0x0065
 #define PCI_DEVICE_ID_NVIDIA_NVENET_2		0x0066