lan78xx: Correctly indicate invalid OTP

[ Upstream commit 4bfc33807a9a02764bdd1e42e794b3b401240f27 ]

lan78xx_read_otp tries to return -EINVAL in the event of invalid OTP
content, but the value gets overwritten before it is returned and the
read goes ahead anyway. Make the read conditional as it should be
and preserve the error code.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index c53385a..f5a9667 100644 (file)
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -873,7 +873,8 @@ static int lan78xx_read_otp(struct lan78xx_net *dev, u32 offset,
                        offset += 0x100;
                else
                        ret = -EINVAL;
-               ret = lan78xx_read_raw_otp(dev, offset, length, data);
+               if (!ret)
+                       ret = lan78xx_read_raw_otp(dev, offset, length, data);
        }
 
        return ret;