[ARM] CATS: Do not try and map bad PCI IRQ numbers
The cats_map_irq() function in the Simtec CATS support
code is mapping IRQ 255 (invalid IRQ) into what is a
supposedly valid interrupt numner which can cause problems
with other devices then seeing an interrupt they cannot
claim.
If the IRQ number if >= 255, then return -1 as this is not
something we can map.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
diff --git a/arch/arm/mach-footbridge/cats-pci.c b/arch/arm/mach-footbridge/cats-pci.c
index 35eb232..ae3e1c8 100644
--- a/arch/arm/mach-footbridge/cats-pci.c
+++ b/arch/arm/mach-footbridge/cats-pci.c
@@ -18,6 +18,9 @@
static int __init cats_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
+ if (dev->irq >= 255)
+ return -1; /* not a valid interrupt. */
+
if (dev->irq >= 128)
return dev->irq & 0x1f;