The EXT_RGMII_OOB_CTRL register can be written from different contexts. It is predominantly written from the adjust_link handler which is synchronized by the phydev->lock, but can also be written from a different context when configuring the mii in bcmgenet_mii_config(). The chances of contention are quite low, but it is conceivable that adjust_link could occur during resume when WoL is enabled so use the phydev->lock synchronizer in bcmgenet_mii_config() to be sure. Fixes: afe3f907d20f ("net: bcmgenet: power on MII block for all MII modes") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Doug Berger <opendmb@xxxxxxxxx> Acked-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> (cherry picked from commit d85cf67a339685beae1d0aee27b7f61da95455be) Signed-off-by: Doug Berger <opendmb@xxxxxxxxx> --- drivers/net/ethernet/broadcom/genet/bcmmii.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c index 51f6c94e919e..6d823c107476 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c @@ -264,6 +264,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) * block for the interface to work */ if (priv->ext_phy) { + mutex_lock(&phydev->lock); reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL); reg &= ~ID_MODE_DIS; reg |= id_mode_dis; @@ -272,6 +273,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) else reg |= RGMII_MODE_EN; bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL); + mutex_unlock(&phydev->lock); } if (init) -- 2.34.1