net: dsa: microchip: Don't try to read stats for unused ports

If some of the switch ports were not listed in the device tree, due to
being unused, the ksz_mib_read_work function ended up accessing a NULL
dp->slave pointer and causing an oops. Skip checking statistics for any
unused ports.

Fixes: 7c6ff470aa ("net: dsa: microchip: add MIB counter reading support")
Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Robert Hancock 2019-06-12 14:33:32 -06:00 committed by David S. Miller
parent 2309f51797
commit 6bb9e376c2

View File

@ -83,6 +83,9 @@ static void ksz_mib_read_work(struct work_struct *work)
int i;
for (i = 0; i < dev->mib_port_cnt; i++) {
if (dsa_is_unused_port(dev->ds, i))
continue;
p = &dev->ports[i];
mib = &p->mib;
mutex_lock(&mib->cnt_mutex);