[PATCH 4.9 07/42] net: mdiobus: get rid of a BUG_ON()

From: Greg Kroah-Hartman
Date: Mon Jun 14 2021 - 06:34:23 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 1dde47a66d4fb181830d6fa000e5ea86907b639e ]

We spotted a bug recently during a review where a driver was
unregistering a bus that wasn't registered, which would trigger this
BUG_ON(). Let's handle that situation more gracefully, and just print
a warning and return.

Reported-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/phy/mdio_bus.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index a9bbdcec0bad..8cc7563ab103 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -362,7 +362,8 @@ void mdiobus_unregister(struct mii_bus *bus)
struct mdio_device *mdiodev;
int i;

- BUG_ON(bus->state != MDIOBUS_REGISTERED);
+ if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
+ return;
bus->state = MDIOBUS_UNREGISTERED;

for (i = 0; i < PHY_MAX_ADDR; i++) {
--
2.30.2