i2c-pca-isa: Add access check to legacy ioports

When probing i2c-pca-isa writes to legacy ioports, which crashes the kernel
if there is no device at that port.
This patch adds a check_legacy_ioport call, so probe fails gracefully
and thus prevents the oops.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index 5161aaf9341b..496ee875eb4f 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -125,6 +125,13 @@ static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
 
         dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq);
 
+#ifdef CONFIG_PPC_MERGE
+        if (check_legacy_ioport(base)) {
+                dev_err(dev, "I/O address %#08lx is not available\n", base);
+                goto out;
+        }
+#endif
+
         if (!request_region(base, IO_SIZE, "i2c-pca-isa")) {
                 dev_err(dev, "I/O address %#08lx is in use\n", base);
                 goto out;