thermal: devfreq_cooling: use local ops instead of global ops
authorKant Fan <kant@allwinnertech.com>
Fri, 25 Mar 2022 07:30:30 +0000 (15:30 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 9 Jun 2022 08:23:26 +0000 (10:23 +0200)
commit8e354518f576307658d79847a3ec94025e42983f
tree725c21becbe2b6dd0fca7835ff43b9d77c417093
parentde23a6a1a31fcf259fa7cdf39f30d743b43971bd
thermal: devfreq_cooling: use local ops instead of global ops

commit b947769b8f778db130aad834257fcaca25df2edc upstream.

Fix access illegal address problem in following condition:

There are multiple devfreq cooling devices in system, some of them has
EM model but others do not. Energy model ops such as state2power will
append to global devfreq_cooling_ops when the cooling device with
EM model is registered. It makes the cooling device without EM model
also use devfreq_cooling_ops after appending when registered later by
of_devfreq_cooling_register_power() or of_devfreq_cooling_register().

The IPA governor regards the cooling devices without EM model as a power
actor, because they also have energy model ops, and will access illegal
address at dfc->em_pd when execute cdev->ops->get_requested_power,
cdev->ops->state2power or cdev->ops->power2state.

Fixes: 615510fe13bd2 ("thermal: devfreq_cooling: remove old power model and use EM")
Cc: 5.13+ <stable@vger.kernel.org> # 5.13+
Signed-off-by: Kant Fan <kant@allwinnertech.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/thermal/devfreq_cooling.c