Date: Thu, 5 Oct 2006 00:44:48 +0200
From: Pavel Machek <pavel@ucw.cz>
To: Oliver Neukum <oliver@neukum.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: error to be returned while suspended
Message-ID: <20061004224448.GL8440@elf.ucw.cz>
References: <200610031323.00547.oliver@neukum.org> <20061004111933.GA8297@elf.ucw.cz> <200610041834.57639.oliver@neukum.org>
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Hi!

> > > which error should a character device return if a read/write cannot be
> > > serviced because the device is suspended? Shouldn't there be an error
> > > code specific to that?
> > 
> > If you are talking system suspend, then userspace should not run while
> > devices are suspended.
> > 
> > If you are talking runtime suspend, you should probably just wake the
> > device up on first access.
> 
> Do you really think a device driver should override an explicitely
> selected power state?

(So we are talking runtime suspend?)

No, I do not know what the right interface is. I started to suspect
that drivers should suspend/resume devices automatically, without
userland help. Maybe having autosuspend_timeout in sysfs is enough.

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