Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH 2/2] cpuidle / menu: Return error code if there are no suitable states | Date | Sun, 27 Apr 2014 14:55:30 +0200 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 <rafael.j.wysocki@intel.com> --- 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 */
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