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From: Stewart Smith <stewart@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com>,
 Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Cc: skiboot@lists.ozlabs.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [Skiboot] [PATCH 1/2] SLW: Remove stop1_lite and stop0 stop states
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Date: Mon, 07 May 2018 01:37:07 +1000
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Michael Ellerman <mpe@ellerman.id.au> writes:
> Stewart Smith <stewart@linux.vnet.ibm.com> writes:
> ...
>>
>> Slightly stupid question: should we be disabling these here or should
>> Linux be better and deciding what states to use?
>>
>> I'm inclined to say this is a Linux problem as it should make the
>> decision of what hardware feature to used based on the ones OPAL says
>> *can* be used.
>
> Yeah I agree.
>
> Firmware shouldn't be implementing the policy around what states to use,
> it should tell the operating system (which might be Linux) what states
> are available and what their features are.

Yeah... I think I should work out somewhere to put this in the
documentation, a kind of design philosophy we can point back to.

> The exception to that would be that we have unfixable crash bugs in
> existing kernels, in that case firmware might have to filter out states
> that are known to cause those.

s/in/with/ and *cough* stop11 for example.

-- 
Stewart Smith
OPAL Architect, IBM.