On 4/15/2024 16:48, Lukas Wunner wrote:
Roman reports a deadlock on unplug of a Thunderbolt docking station containing an Intel I225 Ethernet adapter.The root cause is that led_classdev's for LEDs on the adapter are registered such that they're device-managed by the netdev. That results in recursive acquisition of the rtnl_lock() mutex on unplug: When the driver calls unregister_netdev(), it acquires rtnl_lock(), then frees the device-managed resources. Upon unregistering the LEDs, netdev_trig_deactivate() invokes unregister_netdevice_notifier(), which tries to acquire rtnl_lock() again. Avoid by using non-device-managed LED registration. Stack trace for posterity: schedule+0x6e/0xf0 schedule_preempt_disabled+0x15/0x20 __mutex_lock+0x2a0/0x750 unregister_netdevice_notifier+0x40/0x150 netdev_trig_deactivate+0x1f/0x60 [ledtrig_netdev] led_trigger_set+0x102/0x330 led_classdev_unregister+0x4b/0x110 release_nodes+0x3d/0xb0 devres_release_all+0x8b/0xc0 device_del+0x34f/0x3c0 unregister_netdevice_many_notify+0x80b/0xaf0 unregister_netdev+0x7c/0xd0 igc_remove+0xd8/0x1e0 [igc] pci_device_remove+0x3f/0xb0 Fixes: ea578703b03d ("igc: Add support for LEDs on i225/i226") Reported-by: Roman Lozko <[email protected]> Closes: https://lore.kernel.org/r/CAEhC_B=ksywxcg_+aqqxurgegkq+4mqnsv8ebhokbc3-obj...@mail.gmail.com/ Signed-off-by: Kurt Kanzenbach <[email protected]> Signed-off-by: Lukas Wunner <[email protected]> Cc: Heiner Kallweit <[email protected]> --- drivers/net/ethernet/intel/igc/igc.h | 2 ++ drivers/net/ethernet/intel/igc/igc_leds.c | 38 ++++++++++++++++++++++++------- drivers/net/ethernet/intel/igc/igc_main.c | 3 +++ 3 files changed, 35 insertions(+), 8 deletions(-)
Tested-by: Naama Meir <[email protected]>
