kernel: add MIPS pci fix send upstream

Upstream commit 23dac14d058f ("MIPS: PCI: Use struct list_head lists")
changed the controller list from reverse to straight order without
taking care of the changed order for the scan of the recorded PCI
controllers.

Traverse the list in reverse order to restore the former behaviour.

This patches fixes the following PCI error on lantiq:

  pci 0000:01:00.0: BAR 0: error updating (0x1c000004 != 0x000000)

Signed-off-by: Mathias Kresin <dev@kresin.me>

diff --git a/target/linux/generic/patches-4.9/170-MIPS-PCI-scan-PCI-controllers-in-reverse-order.patch b/target/linux/generic/patches-4.9/170-MIPS-PCI-scan-PCI-controllers-in-reverse-order.patch
new file mode 100644 (file)
index 0000000..74b54e9
--- /dev/null
+++ b/target/linux/generic/patches-4.9/170-MIPS-PCI-scan-PCI-controllers-in-reverse-order.patch
@@ -0,0 +1,31 @@
+From: Mathias Kresin <dev@kresin.me>
+Date: Tue, 14 Mar 2017 22:12:12 +0100
+Subject: [PATCH v2] MIPS: PCI: scan PCI controllers in reverse order
+
+Commit 23dac14d058f ("MIPS: PCI: Use struct list_head lists") changed
+the controller list from reverse to straight order without taking care
+of the changed order for the scan of the recorded PCI controllers.
+
+Traverse the list in reverse order to restore the former behaviour.
+
+This patches fixes the following PCI error on lantiq:
+
+  pci 0000:01:00.0: BAR 0: error updating (0x1c000004 != 0x000000)
+
+Fixes: 23dac14d058f ("MIPS: PCI: Use struct list_head lists")
+Signed-off-by: Mathias Kresin <dev@kresin.me>
+---
+ arch/mips/pci/pci-legacy.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/mips/pci/pci-legacy.c
++++ b/arch/mips/pci/pci-legacy.c
+@@ -222,7 +222,7 @@ static int __init pcibios_init(void)
+       struct pci_controller *hose;
+ 
+       /* Scan all of the recorded PCI controllers.  */
+-      list_for_each_entry(hose, &controllers, list)
++      list_for_each_entry_reverse(hose, &controllers, list)
+               pcibios_scanbus(hose);
+ 
+       pci_fixup_irqs(pci_common_swizzle, pcibios_map_irq);