linux/drivers/net/phy, branch v6.16

net: phy: Don't register LEDs for genphy

2025-07-15T00:53:09Z

If a PHY has no driver, the genphy driver is probed/removed directly in phy_attach/detach. If the PHY's ofnode has an "leds" subnode, then the LEDs will be (un)registered when probing/removing the genphy driver. This could occur if the leds are for a non-generic driver that isn't loaded for whatever reason. Synchronously removing the PHY device in phy_detach leads to the following deadlock: rtnl_lock() ndo_close() ... phy_detach() phy_remove() phy_leds_unregister() led_classdev_unregister() led_trigger_set() netdev_trigger_deactivate() unregister_netdevice_notifier() rtnl_lock() There is a corresponding deadlock on the open/register side of things (and that one is reported by lockdep), but it requires a race while this one is deterministic. Generic PHYs do not support LEDs anyway, so don't bother registering them. Fixes: 01e5b728e9e4 ("net: phy: Add a binding for PHY LEDs") Signed-off-by: Sean Anderson Link: https://patch.msgid.link/20250707195803.666097-1-sean.anderson@linux.dev Signed-off-by: Jakub Kicinski

net: phy: microchip: limit 100M workaround to link-down events on LAN88xx

2025-07-11T01:08:16Z

Restrict the 100Mbit forced-mode workaround to link-down transitions only, to prevent repeated link reset cycles in certain configurations. The workaround was originally introduced to improve signal reliability when switching cables between long and short distances. It temporarily forces the PHY into 10 Mbps before returning to 100 Mbps. However, when used with autonegotiating link partners (e.g., Intel i350), executing this workaround on every link change can confuse the partner and cause constant renegotiation loops. This results in repeated link down/up transitions and the PHY never reaching a stable state. Limit the workaround to only run during the PHY_NOLINK state. This ensures it is triggered only once per link drop, avoiding disruptive toggling while still preserving its intended effect. Note: I am not able to reproduce the original issue that this workaround addresses. I can only confirm that 100 Mbit mode works correctly in my test setup. Based on code inspection, I assume the workaround aims to reset some internal state machine or signal block by toggling speeds. However, a PHY reset is already performed earlier in the function via phy_init_hw(), which may achieve a similar effect. Without a reproducer, I conservatively keep the workaround but restrict its conditions. Fixes: e57cf3639c32 ("net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver") Signed-off-by: Oleksij Rempel Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20250709130753.3994461-3-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski

net: phy: microchip: Use genphy_soft_reset() to purge stale LPA bits

2025-07-11T01:08:16Z

Enable .soft_reset for the LAN88xx PHY driver by assigning genphy_soft_reset() to ensure that the phylib core performs a proper soft reset during reconfiguration. Previously, the driver left .soft_reset unimplemented, so calls to phy_init_hw() (e.g., from lan88xx_link_change_notify()) did not fully reset the PHY. As a result, stale contents in the Link Partner Ability (LPA) register could persist, causing the PHY to incorrectly report that the link partner advertised autonegotiation even when it did not. Using genphy_soft_reset() guarantees a clean reset of the PHY and corrects the false autoneg reporting in these scenarios. Fixes: ccb989e4d1ef ("net: phy: microchip: Reset LAN88xx PHY to ensure clean link state on LAN7800/7850") Signed-off-by: Oleksij Rempel Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20250709130753.3994461-2-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski

net: phy: smsc: Fix link failure in forced mode with Auto-MDIX

2025-07-09T01:12:49Z

Force a fixed MDI-X mode when auto-negotiation is disabled to prevent link instability. When forcing the link speed and duplex on a LAN9500 PHY (e.g., with `ethtool -s eth0 autoneg off ...`) while leaving MDI-X control in auto mode, the PHY fails to establish a stable link. This occurs because the PHY's Auto-MDIX algorithm is not designed to operate when auto-negotiation is disabled. In this state, the PHY continuously toggles the TX/RX signal pairs, which prevents the link partner from synchronizing. This patch resolves the issue by detecting when auto-negotiation is disabled. If the MDI-X control mode is set to 'auto', the driver now forces a specific, stable mode (ETH_TP_MDI) to prevent the pair toggling. This choice of a fixed MDI mode mirrors the behavior the hardware would exhibit if the AUTOMDIX_EN strap were configured for a fixed MDI connection. Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support") Signed-off-by: Oleksij Rempel Cc: Andre Edich Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20250703114941.3243890-4-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski

net: phy: smsc: Force predictable MDI-X state on LAN87xx

2025-07-09T01:12:49Z

Override the hardware strap configuration for MDI-X mode to ensure a predictable initial state for the driver. The initial mode of the LAN87xx PHY is determined by the AUTOMDIX_EN strap pin, but the driver has no documented way to read its latched status. This unpredictability means the driver cannot know if the PHY has initialized with Auto-MDIX enabled or disabled, preventing it from providing a reliable interface to the user. This patch introduces a `config_init` hook that forces the PHY into a known state by explicitly enabling Auto-MDIX. Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support") Signed-off-by: Oleksij Rempel Cc: Andre Edich Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20250703114941.3243890-3-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski

net: phy: smsc: Fix Auto-MDIX configuration when disabled by strap

2025-07-09T01:12:49Z

Correct the Auto-MDIX configuration to ensure userspace settings are respected when the feature is disabled by the AUTOMDIX_EN hardware strap. The LAN9500 PHY allows its default MDI-X mode to be configured via a hardware strap. If this strap sets the default to "MDI-X off", the driver was previously unable to enable Auto-MDIX from userspace. When handling the ETH_TP_MDI_AUTO case, the driver would set the SPECIAL_CTRL_STS_AMDIX_ENABLE_ bit but neglected to set the required SPECIAL_CTRL_STS_OVRRD_AMDIX_ bit. Without the override flag, the PHY falls back to its hardware strap default, ignoring the software request. This patch corrects the behavior by also setting the override bit when enabling Auto-MDIX. This ensures that the userspace configuration takes precedence over the hardware strap, allowing Auto-MDIX to be enabled correctly in all scenarios. Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support") Signed-off-by: Oleksij Rempel Cc: Andre Edich Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20250703114941.3243890-2-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski

net: phy: qcom: qca808x: Fix WoL issue by utilizing at8031_set_wol()

2025-07-07T23:43:47Z

The previous commit unintentionally removed the code responsible for enabling WoL via MMD3 register 0x8012 BIT5. As a result, Wake-on-LAN (WoL) support for the QCA808X PHY is no longer functional. The WoL (Wake-on-LAN) feature for the QCA808X PHY is enabled via MMD3 register 0x8012, BIT5. This implementation is aligned with the approach used in at8031_set_wol(). Fixes: e58f30246c35 ("net: phy: at803x: fix the wol setting functions") Signed-off-by: Luo Jie Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20250704-qcom_phy_wol_support-v1-2-053342b1538d@quicinc.com Signed-off-by: Jakub Kicinski

net: phy: qcom: move the WoL function to shared library

2025-07-07T23:43:47Z

Move the WoL (Wake-on-LAN) functionality to a shared library to enable its reuse by the QCA808X PHY driver, incorporating support for WoL functionality similar to the implementation in at8031_set_wol(). Reviewed-by: Maxime Chevallier Signed-off-by: Luo Jie Link: https://patch.msgid.link/20250704-qcom_phy_wol_support-v1-1-053342b1538d@quicinc.com Signed-off-by: Jakub Kicinski

net: phy: phy_caps: Don't skip better duplex macth on non-exact match

2025-06-12T15:00:53Z

When performing a non-exact phy_caps lookup, we are looking for a supported mode that matches as closely as possible the passed speed/duplex. Blamed patch broke that logic by returning a match too early in case the caller asks for half-duplex, as a full-duplex linkmode may match first, and returned as a non-exact match without even trying to mach on half-duplex modes. Reported-by: Jijie Shao Closes: https://lore.kernel.org/netdev/20250603102500.4ec743cf@fedora/T/#m22ed60ca635c67dc7d9cbb47e8995b2beb5c1576 Tested-by: Jijie Shao Reviewed-by: Larysa Zaremba Fixes: fc81e257d19f ("net: phy: phy_caps: Allow looking-up link caps based on speed and duplex") Signed-off-by: Maxime Chevallier Link: https://patch.msgid.link/20250606094321.483602-1-maxime.chevallier@bootlin.com Signed-off-by: Jakub Kicinski

net/mdiobus: Fix potential out-of-bounds clause 45 read/write access

2025-06-11T11:49:03Z

When using publicly available tools like 'mdio-tools' to read/write data from/to network interface and its PHY via C45 (clause 45) mdiobus, there is no verification of parameters passed to the ioctl and it accepts any mdio address. Currently there is support for 32 addresses in kernel via PHY_MAX_ADDR define, but it is possible to pass higher value than that via ioctl. While read/write operation should generally fail in this case, mdiobus provides stats array, where wrong address may allow out-of-bounds read/write. Fix that by adding address verification before C45 read/write operation. While this excludes this access from any statistics, it improves security of read/write operation. Fixes: 4e4aafcddbbf ("net: mdio: Add dedicated C45 API to MDIO bus drivers") Signed-off-by: Jakub Raczynski Reported-by: Wenjing Shan Signed-off-by: David S. Miller