From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@osdl.org>
Date: Thu, 18 Mar 2004 03:28:21 +0000
Subject: Re: add lowpower_idle sysctl
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List-Id: <linux-ia64.vger.kernel.org>
References: <20040317170436.430acfbe.akpm@osdl.org>
	<200403180318.i2I3IDF03166@unix-os.sc.intel.com>
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To: Kenneth Chen <kenneth.w.chen@intel.com>
Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org

"Kenneth Chen" <kenneth.w.chen@intel.com> wrote:
>
>  > > Logically it means a sysctl entry in /proc/sys/kernel.
>  > Yes, but the *meanings* of the different values of that sysctl need
>  > to be defined, and documented.  If lowpower_idleB has a totally
>  > different meaning on different architectures then that's unfortunate
>  > but understandable.  But we should at least enumerate the different
>  > values and try to get different architectures to honour `42' in the
>  > same way.
> 
>  Writing to sysctl should be a bool, reading the value can be number of
>  module currently disabled low power idle.  I think the original intent
>  is to use ref count for enabling/disabling.  (granted, we copied the
>  code from other arch).

OK, so why not give us:

#define IDLE_HALT			0
#define IDLE_POLL			1
#define IDLE_SUPER_LOW_POWER_HALT	2

and so forth (are there any others?).

Set some system-wide integer via a sysctl and let the particular
architecture decide how best to implement the currently-selected idle mode?