ARM: Kirkwood: Update PCI-E fixup

commit 1dc831bf upstream.

- The code relies on rc_pci_fixup being called, which only happens
  when CONFIG_PCI_QUIRKS is enabled, so add that to Kconfig. Omitting
  this causes a booting failure with a non-obvious cause.
- Update rc_pci_fixup to set the class properly, copying the
  more modern style from other places
- Correct the rc_pci_fixup comment
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/arm/Kconfig

@@ -542,6 +542,7 @@ config ARCH_KIRKWOOD
 	bool "Marvell Kirkwood"
 	select CPU_FEROCEON
 	select PCI
+	select PCI_QUIRKS
 	select ARCH_REQUIRE_GPIOLIB
 	select GENERIC_CLOCKEVENTS
 	select PLAT_ORION

arch/arm/mach-kirkwood/pcie.c

@@ -213,14 +213,19 @@ static int __init kirkwood_pcie_setup(int nr, struct pci_sys_data *sys)
 	return 1;
 }
 
+/*
+ * The root complex has a hardwired class of PCI_CLASS_MEMORY_OTHER, when it
+ * is operating as a root complex this needs to be switched to
+ * PCI_CLASS_BRIDGE_HOST or Linux will errantly try to process the BAR's on
+ * the device. Decoding setup is handled by the orion code.
+ */
 static void __devinit rc_pci_fixup(struct pci_dev *dev)
 {
-	/*
-	 * Prevent enumeration of root complex.
-	 */
 	if (dev->bus->parent == NULL && dev->devfn == 0) {
 		int i;
 
+		dev->class &= 0xff;
+		dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
 		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
 			dev->resource[i].start = 0;
 			dev->resource[i].end   = 0;