net: mdio: Fix lockdep falls positive splat
MDIO devices can be stacked upon each other. The current code supports
two levels, which until recently has been enough for a DSA mdio bus on
top of another bus. Now we have hardware which has an MDIO mux in the
middle.
Define an MDIO MUTEX class with three levels.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 0cba64f..751202a 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -457,7 +457,7 @@
BUG_ON(in_interrupt());
- mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
retval = bus->read(bus, addr, regnum);
mutex_unlock(&bus->mdio_lock);
@@ -509,7 +509,7 @@
BUG_ON(in_interrupt());
- mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
err = bus->write(bus, addr, regnum, val);
mutex_unlock(&bus->mdio_lock);