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Date: Sun, 22 Feb 2009 14:46:18 +0100
From: Pavel Machek <pavel@ucw.cz>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: pm list <linux-pm@lists.linux-foundation.org>,
       LKML <linux-kernel@vger.kernel.org>, Arve Hj?nnev?g <arve@android.com>,
       Alan Stern <stern@rowland.harvard.edu>,
       Benjamin Herrenschmidt <benh@kernel.crashing.org>,
       Nigel Cunningham <nigel@nigel.suspend2.net>,
       Matthew Garrett <mjg59@srcf.ucam.org>,
       mark gross <mgross@linux.intel.com>,
       "Woodruff, Richard" <r-woodruff2@ti.com>, Uli Luckas <u.luckas@road.de>,
       Igor Stoppa <igor.stoppa@nokia.com>,
       Brian Swetland <swetland@google.com>, Len Brown <lenb@kernel.org>
Subject: Re: [RFD] Automatic suspend
Message-ID: <20090222134618.GA1436@ucw.cz>
References: <200902160010.16955.rjw@sisk.pl> <20090216225831.GH1370@ucw.cz> <200902170026.06966.rjw@sisk.pl>
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Hi!

> > > The recent descussion about the Android PM patches sent by Arve shows that
> > > there is a need to introduce a mechanism allowing us to:
> > > (1) automatically put the system as a whole into a sleep state (eg. suspend to
> > >     RAM) when it is found to be "idle", where the meaning of "idle" has to be
> > >     defined too,
> > 
> > Well; I'd prefer to keep the interface very minimal.
> > 
> > If no devices are being used,
> 
> We'll need some kind of infrastructure to detect such situations.

Yes, I like the latest 'atomic_t + bit in struct device' ideas...
 
> > and next wakeup is far enough in the future,
> 
> What exactly do you mean by "next wakeup"?

Next timer in kernel and next sleep/select timeout in userspace.

								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html