b44: Truncate PHY address

Some ROMs on embedded devices store incorrect values for
the PHY address of the ethernet device.
It looks like the number is sign-extended.
Truncate the value by applying the PHY-address mask to it.
The patch was tested on a bcm47xx embedded system (where the bug
triggers) and a bcm4400 PCI card.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index ea2a2b548e3c..25f1337cd02c 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -2082,6 +2082,11 @@ static int __devinit b44_get_invariants(struct b44 *bp)
                 addr = sdev->bus->sprom.et0mac;
                 bp->phy_addr = sdev->bus->sprom.et0phyaddr;
         }
+        /* Some ROMs have buggy PHY addresses with the high
+         * bits set (sign extension?). Truncate them to a
+         * valid PHY address. */
+        bp->phy_addr &= 0x1F;
+
         memcpy(bp->dev->dev_addr, addr, 6);
 
         if (!is_valid_ether_addr(&bp->dev->dev_addr[0])){