dsa: do not dereference non-existing routing table

In the case where there is only one switch, no routing table will have
been allocated, so do not dereference it in this case.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/dsa/mv88e6131.c b/drivers/net/dsa/mv88e6131.c
index 1230f52aa70e..2540ef0142af 100644
--- a/drivers/net/dsa/mv88e6131.c
+++ b/drivers/net/dsa/mv88e6131.c
@@ -139,7 +139,8 @@ static int mv88e6131_setup_global(struct dsa_switch *ds)
                 int nexthop;
 
                 nexthop = 0x1f;
-                if (i != ds->index && i < ds->dst->pd->nr_chips)
+                if (ds->pd->rtable &&
+                    i != ds->index && i < ds->dst->pd->nr_chips)
                         nexthop = ds->pd->rtable[i] & 0x1f;
 
                 REG_WRITE(REG_GLOBAL2, 0x06, 0x8000 | (i << 8) | nexthop);