From: Rafael J. Wysocki <[email protected]> If there is a PM QoS latency limit and all of the sufficiently shallow C-states are disabled, the cpuidle menu governor returns 0 which on some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned if that C-state has been disabled.
Fix the issue by modifying the menu governor to return an error code in such situations. Signed-off-by: Rafael J. Wysocki <[email protected]> --- drivers/cpuidle/governors/menu.c | 2 +- include/linux/cpuidle.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) Index: linux-pm/drivers/cpuidle/governors/menu.c =================================================================== --- linux-pm.orig/drivers/cpuidle/governors/menu.c +++ linux-pm/drivers/cpuidle/governors/menu.c @@ -296,7 +296,7 @@ static int menu_select(struct cpuidle_dr data->needs_update = 0; } - data->last_state_idx = 0; + data->last_state_idx = CPUIDLE_DRIVER_STATE_POLL; /* Special case when user has set very strict latency requirement */ if (unlikely(latency_req == 0)) Index: linux-pm/include/linux/cpuidle.h =================================================================== --- linux-pm.orig/include/linux/cpuidle.h +++ linux-pm/include/linux/cpuidle.h @@ -217,8 +217,10 @@ static inline int cpuidle_register_gover #ifdef CONFIG_ARCH_HAS_CPU_RELAX #define CPUIDLE_DRIVER_STATE_START 1 +#define CPUIDLE_DRIVER_STATE_POLL 0 #else #define CPUIDLE_DRIVER_STATE_START 0 +#define CPUIDLE_DRIVER_STATE_POLL (-ENXIO) #endif #endif /* _LINUX_CPUIDLE_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
