The inline cpu_pm_register_notifier stub simply allows compilation on systems with CONFIG_CPU_PM disabled. The dummy cpu_pm_register_notifier does not register an trap_pm_init, r4k_tlb_init_pm and r4k_cache_init_pm at all.The inline cpu_pm_register_notifier should return to indicate lack of support when attempting to register an cpu_pm_register_notifier on such a system with CONFIG_CPU_PM disabled. The return value of cpu_pm_register_notifier is in trap_pm_init, r4k_tlb_init_pm and r4k_cache_init_pm where CONFIG_CPU_PM is disable, all other places do not care about the return value. So cpu_pm_register_notifier must returning -ENODEV. Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> --- include/linux/cpu_pm.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/cpu_pm.h b/include/linux/cpu_pm.h index 455b233..206c264 100644 --- a/include/linux/cpu_pm.h +++ b/include/linux/cpu_pm.h @@ -20,6 +20,7 @@ #include <linux/kernel.h> #include <linux/notifier.h> +#include <linux/errno.h> /* * When a CPU goes to a low power state that turns off power to the CPU's @@ -78,7 +79,7 @@ int cpu_cluster_pm_exit(void); static inline int cpu_pm_register_notifier(struct notifier_block *nb) { - return 0; + return -ENODEV; } static inline int cpu_pm_unregister_notifier(struct notifier_block *nb) -- 1.9.1