Date: Wed, 30 Mar 2016 16:17:45 +0800
From: Jisheng Zhang <jszhang@marvell.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
        Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
        Catalin Marinas <Catalin.Marinas@arm.com>
CC: <linux@arm.linux.org.uk>, <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case
 during init
Message-ID: <20160330161745.7afd6e48@xhacker>
In-Reply-To: <56FB89A8.90209@linaro.org>
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	<56F52502.3060308@linaro.org>	<20160330151629.0b338365@xhacker>
	<56FB89A8.90209@linaro.org>
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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?

Thanks for reviewing,
Jisheng