# \[PATCH net-next v20 02/13\] phylib: Add support for PHYs with broken forced mode - From: Birger Koblitz \ - Date: 2026-11-06 07:21:35 - List: netdev - Page: https://ratatoskr.run/netdev/2026/11/17876242 - Thread: https://ratatoskr.run/linux-usb/2026/11/17876248/t.md ```text Add support for PHYs which only supported auto-negotiated speed modes. This prevents a kernel warning and stack-trace within the phy_state_machine when PHYs return -EOPNOTSUPP from config_aneg() because they do not support forced modes. Signed-off-by: Birger Koblitz Reviewed-by: Andrew Lunn Reviewed-by: Nicolai Buchwitz --- drivers/net/phy/phy.c | 7 +++++++ include/linux/phy.h | 1 + 2 files changed, 8 insertions(+) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index fce9bc7be3304b408c9f3ec9b5b95c76d3680a88..079c53516f424ca5f8d50292f1912af04b45b07a 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -354,6 +354,9 @@ int phy_mii_ioctl(struct phy_device *phydev, struct ifreq *ifr, int cmd) switch (devad) { case MII_BMCR: if ((val & (BMCR_RESET | BMCR_ANENABLE)) == 0) { + if (phydev->drv && + (phydev->drv->flags & PHY_BROKEN_FORCED)) + return -EOPNOTSUPP; if (phydev->autoneg == AUTONEG_ENABLE) change_autoneg = true; phydev->autoneg = AUTONEG_DISABLE; @@ -1190,6 +1193,10 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev, duplex != DUPLEX_FULL))) return -EINVAL; + if (autoneg == AUTONEG_DISABLE && phydev->drv && + (phydev->drv->flags & PHY_BROKEN_FORCED)) + return -EOPNOTSUPP; + mutex_lock(&phydev->lock); phydev->autoneg = autoneg; diff --git a/include/linux/phy.h b/include/linux/phy.h index 21afc2082b1741ff276a9588246c2f98351464f5..f1b1ad1dd82f5c51ddd2f0759666e17802894c96 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -64,6 +64,7 @@ extern const int phy_basic_ports_array[3]; #define PHY_RST_AFTER_CLK_EN 0x00000002 #define PHY_POLL_CABLE_TEST 0x00000004 #define PHY_ALWAYS_CALL_SUSPEND 0x00000008 +#define PHY_BROKEN_FORCED 0x00000010 #define MDIO_DEVICE_IS_PHY 0x80000000 /** -- 2.47.3 ```