Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init

From	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init
Date	2016-03-30 12:40 +0200
Message-ID	<rilHA-3WZ-37@gated-at.bofh.it> (permalink)
References	<rg5QC-6d1-1@gated-at.bofh.it> <rg5QC-6d1-9@gated-at.bofh.it> <rgypA-14r-7@gated-at.bofh.it> <riiJH-215-3@gated-at.bofh.it> <rijw6-2y5-31@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Mar 30, 2016 at 10:09:12AM +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.
> 
> 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.

I agree and I think it makes sense to have an arm back-end that fails
if there is no cpuidle_ops.init function registered, I doubt any
usage of the cpuidle_ops.suspend is reasonable if it was not
initialized by a corresponding cpuidle_ops.init at boot, at least
that's how I see it working, I am open to other point of views.

Thanks,
Lorenzo

Thread

[PATCH 0/2] ARM: cpuidle: bug fix and a trivial improvement Jisheng Zhang <jszhang@marvell.com> - 2016-03-24 06:20 +0100
  [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init Jisheng Zhang <jszhang@marvell.com> - 2016-03-24 06:20 +0100
    Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during  init Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-03-25 12:50 +0100
      Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case  during init Jisheng Zhang <jszhang@marvell.com> - 2016-03-30 09:30 +0200
        Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during  init Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-03-30 10:20 +0200
          Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case  during init Jisheng Zhang <jszhang@marvell.com> - 2016-03-30 10:30 +0200
            Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case  during init Jisheng Zhang <jszhang@marvell.com> - 2016-03-30 10:50 +0200
              Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during  init Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-03-30 11:40 +0200
                Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case  during init Jisheng Zhang <jszhang@marvell.com> - 2016-03-30 11:50 +0200
            Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during  init Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-03-30 10:50 +0200
          Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during  init Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-03-30 12:40 +0200
  [PATCH 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang <jszhang@marvell.com> - 2016-03-24 06:20 +0100
    Re: [PATCH 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more  efficient Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-03-25 13:00 +0100

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