6.9-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
commit fcf2a9970ef587d8f358560c381ee6115a9108aa upstream.
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@s... 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/leds/led-class.c | 6 ------ 1 file changed, 6 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 24fcff682b24..ba1be15cfd8e 100644 --- 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