6.15-stable review patch. If anyone has any objections, please let me know.
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From: Sean Anderson sean.anderson@linux.dev
[ Upstream commit f0f2b992d8185a0366be951685e08643aae17d6d ]
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 sean.anderson@linux.dev Link: https://patch.msgid.link/20250707195803.666097-1-sean.anderson@linux.dev Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/phy_device.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 7d5e76a3db0e9..2f5bb4d0911d2 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -3391,7 +3391,8 @@ static int phy_probe(struct device *dev) /* Get the LEDs from the device tree, and instantiate standard * LEDs for them. */ - if (IS_ENABLED(CONFIG_PHYLIB_LEDS)) + if (IS_ENABLED(CONFIG_PHYLIB_LEDS) && !phy_driver_is_genphy(phydev) && + !phy_driver_is_genphy_10g(phydev)) err = of_phy_leds(phydev);
out: @@ -3408,7 +3409,8 @@ static int phy_remove(struct device *dev)
cancel_delayed_work_sync(&phydev->state_queue);
- if (IS_ENABLED(CONFIG_PHYLIB_LEDS)) + if (IS_ENABLED(CONFIG_PHYLIB_LEDS) && !phy_driver_is_genphy(phydev) && + !phy_driver_is_genphy_10g(phydev)) phy_leds_unregister(phydev);
phydev->state = PHY_DOWN;