net: usb: lan78xx: Fix lost EEPROM write timeout error(-ETIMEDOUT) in lan78xx_write_r...

The function lan78xx_write_raw_eeprom failed to properly propagate EEPROM
write timeout errors (-ETIMEDOUT). In the timeout  fallthrough path, it first
attempted to restore the pin configuration for LED outputs and then
returned only the status of that restore operation, discarding the
original timeout error saved in ret.

As a result, callers could mistakenly treat EEPROM write operation as
successful even though the EEPROM write had actually timed out with no
or partial data write.

To fix this, handle errors in restoring the LED pin configuration separately.
If the restore succeeds, return any prior EEPROM write timeout error saved
in ret to the caller.

Suggested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Fixes: 8b1b2ca83b20 ("net: usb: lan78xx: Improve error handling in EEPROM and OTP operations")
cc: stable@vger.kernel.org
Signed-off-by: Bhanu Seshu Kumar Valluri <bhanuseshukumar@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 42d35cc6b421c2f2b7e7edfd249d27048087e2fa..28195d9a8d6bc50b6d39c6ad216d0e527fc54d6c 100644 (file)
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1175,10 +1175,13 @@ static int lan78xx_write_raw_eeprom(struct lan78xx_net *dev, u32 offset,
        }
 
 write_raw_eeprom_done:
-       if (dev->chipid == ID_REV_CHIP_ID_7800_)
-               return lan78xx_write_reg(dev, HW_CFG, saved);
-
-       return 0;
+       if (dev->chipid == ID_REV_CHIP_ID_7800_) {
+               int rc = lan78xx_write_reg(dev, HW_CFG, saved);
+               /* If USB fails, there is nothing to do */
+               if (rc < 0)
+                       return rc;
+       }
+       return ret;
 }
 
 static int lan78xx_read_raw_otp(struct lan78xx_net *dev, u32 offset,