On Fri, Jun 07, 2024 at 12:18:47PM +0200, Hans de Goede wrote:
> 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@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/9d189ec329cfe68ed68699f314e191a10d4b5eda.camel@xxxxxxxxxxxx/
> Reported-by: "Johannes Wüller" <johanneswueller@xxxxxxxxx>
> Closes: https://lore.kernel.org/lkml/e441605c-eaf2-4c2d-872b-d8e541f4cf60@xxxxxxxxx/
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
I'm not sure i agree with the Closes: All this does is make it less
likely to deadlock. The deadlock is still there. But:
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Andrew
