Messages in this thread | | | Subject | Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init | From | Daniel Lezcano <> | Date | Wed, 30 Mar 2016 11:31:39 +0200 |
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On 03/30/2016 10:43 AM, Jisheng Zhang wrote: > On Wed, 30 Mar 2016 10:41:09 +0200 Daniel Lezcano wrote: > >> On 03/30/2016 10:17 AM, Jisheng Zhang wrote: >>> On Wed, 30 Mar 2016 10:09:12 +0200 Daniel Lezcano wrote: >>> >>>> On 03/30/2016 09:16 AM, Jisheng Zhang wrote: >>>>> Hi Daniel, >>>> >>>> [ ... ] >>>> >>>> Added Lorenzo and Catalin. >>>> >>>>>> Hi Jisheng, >>>>>> >>>>>> this should be handled in the arm_cpuidle_read_ops function. >>>>>> >>>>> >>>>> Thanks for reviewing. After some consideration, I think this patch isn't correct >>>>> There may be platforms which doesn't need the init member at all, although >>>>> currently I don't see such platforms in mainline, So I'll drop this patch >>>>> and send out one v2 only does the optimization. >>>> >>>> There is an inconsistency between ARM and ARM64. The 'cpu_get_ops', the >>>> arm_cpuidle_read_ops from the ARM64 side, returns -EOPNOTSUPP when the >>>> init function is not there for cpuidle. >>> >>> yes. >>> arm64's arm_cpuidle_init() returns -EOPNOTSUPP if init callback isn't defined >>> >>>> >>>> I don't think it is a problem, but as ARM/ARM64 are sharing the same >>>> cpuidle-arm.c driver it would make sense to unify the behavior between >>>> both archs. >>> >>> yes, agree with you. From "unify" point of view, could I move back the suspend >>> callback check and init callback check into arm_cpuidle_init() for arm as V1 does? >> >> Why ? To be consistent with ARM64 ? > > Yes, that's my intention.
Well, I don't have a strong opinion on that. ARM64 cpu_ops is slightly different from cpuidle_ops as the cpu boot / hotplug operations are placed in a different place and that explains why on ARM64 we can have an successful 'get_ops' because we use the partially filled structure. On ARM, it is cpuidle_ops only, so we can gracefully fail if the ops are not defined.
IMO, it still make sense to keep the checks in arm_cpuidle_read_ops for ARM.
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