[ Upstream commit ff91e1b684 ]
The cross-chip notifier boilerplate code meant to check the presence of
ds->ops->port_mrp_add_ring_role before calling it, but checked
ds->ops->port_mrp_add instead, before calling
ds->ops->port_mrp_add_ring_role.
Therefore, a driver which implements one operation but not the other
would trigger a NULL pointer dereference.
There isn't any such driver in DSA yet, so there is no reason to
backport the change. Issue found through code inspection.
Cc: Horatiu Vultur <horatiu.vultur@microchip.com>
Fixes: c595c4330d ("net: dsa: add MRP support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>