From mboxrd@z Thu Jan 1 00:00:00 1970
From: daniel.lezcano@linaro.org (Daniel Lezcano)
Date: Mon, 23 Mar 2015 15:42:01 +0100
Subject: [PATCH V3 7/8] ARM: cpuidle: Register per cpuidle device
In-Reply-To: <20150321203546.GE22354@red-moon>
References: <1426851841-2072-1-git-send-email-daniel.lezcano@linaro.org>
<1426851841-2072-8-git-send-email-daniel.lezcano@linaro.org>
<20150321203546.GE22354@red-moon>
Message-ID: <55102639.4000305@linaro.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org
On 03/21/2015 09:35 PM, Lorenzo Pieralisi wrote:
> On Fri, Mar 20, 2015 at 11:44:00AM +0000, Daniel Lezcano wrote:
>> Some architectures have some cpus which does not support idle states.
>>
>> Let the underlying low level code to return -ENXIO when it is not
>> possible to set an idle state.
>
> Well, this is getting interesting. We are parsing possible CPUs to
> detect if they have common idle states in DT. If a CPU does not support
> idle states, the cpu node for that CPU should not define any idle
> state.
>
> The approach above will work with my heterogenous system patch, since
> the respective CPUidle driver mask will be created by parsing the DT
> idle states.
>
> http://www.spinics.net/lists/arm-kernel/msg403190.html
>
> In current approach if a "possible " CPU does not have idle states, we do
> not init CPUidle at all.
>
> So, to cut a long story short, what does "a cpu does not support idle
> states" mean ?
>
> Does it mean that firmware defines idle states for that CPU in DT but
> initializing them fail ?
>
> I am fine with this patch, but we need to define -ENXIO return properly.
Ok, I think that needs more discussion.
I will drop this patch from my patchset as we agreed on the other
patches and resubmit.
-- Daniel
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