net: dsa: mv88e6xxx: add an error code check in mv88e6352_tai_event_work

mv88e6xxx_tai_write() can return error code (-EOPNOTSUPP ...) if failed.
So check the value of 'ret' after calling mv88e6xxx_tai_write().

Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/mv88e6xxx/ptp.c b/drivers/net/dsa/mv88e6xxx/ptp.c
index ea17231dc34e3e10a3e4d40a36d36d822cbc36b9..56391e09b3257eefe51d88282fe11ef82bf30dbc 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/ptp.c
+++ b/drivers/net/dsa/mv88e6xxx/ptp.c
@@ -182,6 +182,10 @@ static void mv88e6352_tai_event_work(struct work_struct *ugly)
        mv88e6xxx_reg_lock(chip);
        err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS, status[0]);
        mv88e6xxx_reg_unlock(chip);
+       if (err) {
+               dev_err(chip->dev, "failed to write TAI status register\n");
+               return;
+       }
 
        /* This is an external timestamp */
        ev.type = PTP_CLOCK_EXTTS;