net: dsa: mv88e6xxx: get serdes lane after lock

This is a follow-up patch for commit 4e3bd5e755d8 ("net: dsa:
mv88e6xxx: create serdes_get_lane chip operation").

The .serdes_get_lane implementations access the CMODE of a port,
even though it is cached at the moment, it is safer to call them
after the mutex is locked, not before.

At the same time, check for an eventual error and return IRQ_DONE,
instead of blindly ignoring it.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 9424e401dbc7f25d52436d46da006249f561da20..38c0da2492c06127ddc3b0a5899e9892d47a82aa 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -646,10 +646,12 @@ static irqreturn_t mv88e6390_serdes_thread_fn(int irq, void *dev_id)
        int err;
        u8 lane;
 
-       mv88e6xxx_serdes_get_lane(chip, port->port, &lane);
-
        mv88e6xxx_reg_lock(chip);
 
+       err = mv88e6xxx_serdes_get_lane(chip, port->port, &lane);
+       if (err)
+               goto out;
+
        switch (cmode) {
        case MV88E6XXX_PORT_STS_CMODE_SGMII:
        case MV88E6XXX_PORT_STS_CMODE_1000BASEX: