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@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
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@lunn.ch
Andrew