From: Sebastian Andrzej Siewior <bige...@linutronix.de>
cpufreq holds get_online_cpus() while invoking cpuhp_setup_state_nocalls()
to make subsys_interface_register() and the registration of hotplug calls
atomic versus cpu hotplug.
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup_state_nocalls_locked() to avoid the nested call.
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
Cc: Viresh Kumar <viresh.ku...@linaro.org>
Cc: linux...@vger.kernel.org
---
drivers/cpufreq/cpufreq.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2473,9 +2473,10 @@ int cpufreq_register_driver(struct cpufr
goto err_if_unreg;
}
- ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "cpufreq:online",
- cpuhp_cpufreq_online,
- cpuhp_cpufreq_offline);
+ ret = cpuhp_setup_state_nocalls_locked(CPUHP_AP_ONLINE_DYN,
+ "cpufreq:online",
+ cpuhp_cpufreq_online,
+ cpuhp_cpufreq_offline);
if (ret < 0)
goto err_if_unreg;
hp_online = ret;
@@ -2519,7 +2520,7 @@ int cpufreq_unregister_driver(struct cpu
get_online_cpus();
subsys_interface_unregister(&cpufreq_interface);
remove_boost_sysfs_file();
- cpuhp_remove_state_nocalls(hp_online);
+ cpuhp_remove_state_nocalls_locked(hp_online);
write_lock_irqsave(&cpufreq_driver_lock, flags);
