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

commit d5d790ba1558dbb8d179054f514476e2ee970b8e upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index d75502ebbc0d92c05cf6716f6031263209585adc..5ccbe6ae2ebe969d8e91436fe784a302d136b930 100644 (file)
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1174,10 +1174,13 @@ 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,