openwrt/target/linux/ar71xx/patches-3.8/015-MIPS-avoid-possible-resource-conflict-in-register_pc.patch

From 4da85831c8eaf2de2cadae6723e8231068c313b7 Mon Sep 17 00:00:00 2001
From: Gabor Juhos <juhosg@openwrt.org>
Date: Sat, 2 Feb 2013 13:18:54 +0000
Subject: [PATCH] MIPS: avoid possible resource conflict in
 register_pci_controller

commit 222831787704c9ad9215f6b56f975b233968607c upstream.

The IO and memory resources of a PCI controller
might already have a parent resource set when
they are passed to 'register_pci_controller'.

If the parent resource is set, the request_resource
call will fail due to resource conflict and the
current code will not be able to register the
PCI controller.

Use the parent resource if it is available in the
request_resource call to avoid the isssue.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4910/
Signed-off-by: John Crispin <blogic@openwrt.org>
---
 arch/mips/pci/pci.c |   15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -175,9 +175,20 @@ static DEFINE_MUTEX(pci_scan_mutex);
 
 void register_pci_controller(struct pci_controller *hose)
 {
-	if (request_resource(&iomem_resource, hose->mem_resource) < 0)
+	struct resource *parent;
+
+	parent = hose->mem_resource->parent;
+	if (!parent)
+		parent = &iomem_resource;
+
+	if (request_resource(parent, hose->mem_resource) < 0)
 		goto out;
-	if (request_resource(&ioport_resource, hose->io_resource) < 0) {
+
+	parent = hose->io_resource->parent;
+	if (!parent)
+		parent = &ioport_resource;
+
+	if (request_resource(parent, hose->io_resource) < 0) {
 		release_resource(hose->mem_resource);
 		goto out;
 	}