Subject: Re: Changes to PM layer break userspace
From: Arjan van de Ven <arjan@infradead.org>
To: Alan <alan@lxorguk.ukuu.org.uk>
Cc: David Brownell <david-b@pacbell.net>, Pavel Machek <pavel@suse.cz>,
       Matthew Garrett <mjg59@srcf.ucam.org>, linux-kernel@vger.kernel.org,
       gregkh@suse.de
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Organization: Intel International BV
Date: Thu, 28 Dec 2006 17:04:48 +0100
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On Thu, 2006-12-28 at 13:31 +0000, Alan wrote:
> > Seems to me anyone really desperate to put PCI devices into a low
> > power mode, without driver support at the "ifdown" level, would be
> > able just "rmmod driver; setpci".  
> 
> Incorrect for very obvious reasons - there may be two devices driven by
> the same driver one up and one down.

btw this same "incorrect" applies to the sysfs method, that also does a
more or less uncontrolled/uncoordinated power state switch.

All the more reason to have the "normal" device interfaces do the right
thing, so that the kernel has a standing chance to coordinate it
properly.

-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

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