[ARM] 4454/1: Use word accesses in Versatile PCI config reads

ARM Versatile PCI config reads of one byte width have the lowest two bits of the address cleared and result in reading from a wrong place in the config space. This change is to use word size accesses like it is done for halfword reads. Byte reads are used for retrieving the IRQ number of a PCI device and the problem was not exposed until 2.6.20 because the value read was discarded in drivers/pci/setup-irq.c (recently fixed). Signed-off-by: Andrzej Zaborowski <[email protected]> Acked-by: Paul Brook <[email protected]> Signed-off-by: Russell King <[email protected]>
maraz · Jul 2, 2007 · 756813c · 756813c
1 parent a38d618
commit 756813c
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/arch/arm/mach-versatile/pci.c b/arch/arm/mach-versatile/pci.c
@@ -117,7 +117,10 @@ static int versatile_read_config(struct pci_bus *bus, unsigned int devfn, int wh
 	} else {
 		switch (size) {
 		case 1:
-			v = __raw_readb(addr);
+			v = __raw_readl(addr);
+			if (where & 2) v >>= 16;
+			if (where & 1) v >>= 8;
+ 			v &= 0xff;
 			break;
 
 		case 2: