From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 17 May 2021 09:04:13 +0000 (+0300)
Subject: net: mdiobus: get rid of a BUG_ON()
X-Git-Tag: v4.19.195~58
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=acb503deb002ca30e1544dade6059d9cd5d746bd;p=users%2Fdwmw2%2Flinux.git

net: mdiobus: get rid of a BUG_ON()

[ 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@armlinux.org.uk>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 5c89a310359de..08c81d4cfca86 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -446,7 +446,8 @@ 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++) {