leds: class: Revert: "If no default trigger is given, make hw_control trigger the...

Commit 66601a29bb23 ("leds: class: If no default trigger is given, make
hw_control trigger the default trigger") causes ledtrig-netdev to get
set as default trigger on various network LEDs.

This causes users to hit a pre-existing AB-BA deadlock issue in
ledtrig-netdev between the LED-trigger locks and the rtnl mutex,
resulting in hung tasks in kernels >= 6.9.

Solving the deadlock is non trivial, so for now revert the change to
set the hw_control trigger as default trigger, so that ledtrig-netdev
no longer gets activated automatically for various network LEDs.

The netdev trigger is not needed because the network LEDs are usually under
hw-control and the netdev trigger tries to leave things that way so setting
it as the active trigger for the LED class device is a no-op.

Fixes: 66601a29bb23 ("leds: class: If no default trigger is given, make hw_control trigger the default trigger")
Reported-by: Genes Lists <lists@sapience.com>
Closes: https://lore.kernel.org/all/9d189ec329cfe68ed68699f314e191a10d4b5eda.camel@sapience.com/
Reported-by: Johannes Wüller <johanneswueller@gmail.com>
Closes: https://lore.kernel.org/lkml/e441605c-eaf2-4c2d-872b-d8e541f4cf60@gmail.com/
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 24fcff682b24adc6bd271a7496ba6a27f30e0d58..ba1be15cfd8ea36c1426c4db541346665d54d4e1 100644 (file)
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -552,12 +552,6 @@ int led_classdev_register_ext(struct device *parent,
        led_init_core(led_cdev);
 
 #ifdef CONFIG_LEDS_TRIGGERS
-       /*
-        * If no default trigger was given and hw_control_trigger is set,
-        * make it the default trigger.
-        */
-       if (!led_cdev->default_trigger && led_cdev->hw_control_trigger)
-               led_cdev->default_trigger = led_cdev->hw_control_trigger;
        led_trigger_set_default(led_cdev);
 #endif