[PATCH net-next 2/3] net: dsa: mxl862xx: don't skip early bridge port configuration

[Daniel Golle]

mxl862xx_bridge_port_set() is currently guarded by the
mxl8622_port->setup_done flag, as the early call to
mxl862xx_bridge_port_set() from mxl862xx_port_stp_state_set() would
otherwise cause a NULL-pointer dereference on unused ports which don't
have dp->cpu_dp despite not being a CPU port.

Using the setup_done flag (which is never set for unused ports),
however, also prevents mxl862xx_bridge_port_set() from configuring
user ports' single-port bridges early, which was unintended.

Fix this by returning early from mxl862xx_bridge_port_set() in case
dsa_port_is_unused().

Fixes: 340bdf984613c ("net: dsa: mxl862xx: implement bridge offloading")
Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
---
 drivers/net/dsa/mxl862xx/mxl862xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mxl862xx/mxl862xx.c b/drivers/net/dsa/mxl862xx/mxl862xx.c
index 9a9714c4859b1..f65525aff5e52 100644
--- a/drivers/net/dsa/mxl862xx/mxl862xx.c
+++ b/drivers/net/dsa/mxl862xx/mxl862xx.c
@@ -278,7 +278,7 @@ static int mxl862xx_set_bridge_port(struct dsa_switch *ds, int port)
 	bool enable;
 	int i, idx;
 
-	if (!p->setup_done)
+	if (dsa_port_is_unused(dp))
 		return 0;
 
 	if (dsa_port_is_cpu(dp)) {
-- 
2.53.0