v2: - Remove the retry loop in the store method. This patchset works around a circular lock dependency issue in the cpufreq driver reported by lockdep. The two locks involved are the cpu_hotplup_lock and the reference count of a sysfs file.
The cpufreq_register_driver() function uses the lock sequence: cpus_read_lock --> kn->count Whereas the cpufreq sysfs store method uses the sequence: kn->count --> cpus_read_lock This is not really an issue as a shared lock is used on the cpu_hotplup_lock. However, the lockdep code isn't able to handle shared locking. So one way to work around this is to define a cpus_read_trylock() function and uses it in the store method instead. Waiman Long (2): cpu/hotplug: Add a cpus_read_trylock() function cpufreq: Fix a circular lock dependency problem drivers/cpufreq/cpufreq.c | 7 ++++++- include/linux/cpu.h | 2 ++ kernel/cpu.c | 6 ++++++ 3 files changed, 14 insertions(+), 1 deletion(-) -- 1.8.3.1
