Re: [patch 2.6.18-rc2-mm 1/2] PM: make /sys/devices/.../power/state optional

[Pavel Machek <pavel@ucw.cz>]

Hi!

> > > Add a new PM_SYSFS_DEPRECATED config option to control whether or
> > > not the /sys/devices/.../power/state files are provided.  ...
> > 
> > Looks good to me, ACK.
> > 
> > (And sorry for long delay). 
> 
> Greg still hasn't merged it; so, no prob.  :)
> 
> I updated patch 2/2  so that it doesn't test for the problematic and
> incomplete prepare_suspend() method, and to remove prepare_suspend().
> (That removal was discussed separately.)
> 
> 
> 
> > I guess this should go with it...? OTOH andrew wanted alternative,
> > first, before removing the feature... but it is unclear to me if we
> > want the feature at all on the production system, so...
> 
> How about this one instead?  The issue is not limited to that sysfs
> file and its use of PM_EVENT_* codes, that's just the most visible
> facet of the problem.

Looks good to me.

> Index: o26/Documentation/feature-removal-schedule.txt
> ===================================================================
> --- o26.orig/Documentation/feature-removal-schedule.txt	2006-07-30 22:08:10.000000000 -0700
> +++ o26/Documentation/feature-removal-schedule.txt	2006-08-16 11:34:54.000000000 -0700
> @@ -6,6 +6,21 @@ be removed from this file.
>  
>  ---------------------------
>  
> +What:	/sys/devices/.../power/state
> +	dev->power.power_state
> +	dpm_runtime_{suspend,resume)()
> +When:	July 2007
> +Why:	Broken design for runtime control over driver power states, confusing
> +	driver-internal runtime power management with:  mechanisms to support
> +	system-wide sleep state transitions; event codes that distinguish
> +	different phases of swsusp "sleep" transitions; and userspace policy
> +	inputs.  This framework was never widely used, and most attempts to
> +	use it were broken.  Drivers should instead be exposing domain-specific
> +	interfaces either to kernel or to userspace, iff they are even needed.
> +Who:	Pavel Machek <pavel@suse.cz>
> +
> +---------------------------
> +
>  What:	RAW driver (CONFIG_RAW_DRIVER)
>  When:	December 2005
>  Why:	declared obsolete since kernel 2.6.3

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