| Message ID | 20240425221007.2140041-2-opendmb@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: bcmgenet: protect contended accesses | expand |
On Thu, Apr 25, 2024 at 03:10:05PM -0700, Doug Berger wrote: > 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@vger.kernel.org > Signed-off-by: Doug Berger <opendmb@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org>
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c index 9ada89355747..86a4aa72b3d4 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c @@ -2,7 +2,7 @@ /* * Broadcom GENET MDIO routines * - * Copyright (c) 2014-2017 Broadcom + * Copyright (c) 2014-2024 Broadcom */ #include <linux/acpi.h> @@ -275,6 +275,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) * block for the interface to work, unconditionally clear the * Out-of-band disable since we do not need it. */ + mutex_lock(&phydev->lock); reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL); reg &= ~OOB_DISABLE; if (priv->ext_phy) { @@ -286,6 +287,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) reg |= RGMII_MODE_EN; } bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL); + mutex_unlock(&phydev->lock); if (init) dev_info(kdev, "configuring instance for %s\n", phy_name);
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@vger.kernel.org Signed-off-by: Doug Berger <opendmb@gmail.com> --- drivers/net/ethernet/broadcom/genet/bcmmii.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)