From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: Power Management framework proposal Date: Mon, 30 Jul 2007 02:05:20 +0100 Message-ID: <20070730010520.GC27398@srcf.ucam.org> References: <1185125189.2714.13.camel@laptopd505.fenrus.org> <1185143240.2714.24.camel@laptopd505.fenrus.org> <1185163239.2714.37.camel@laptopd505.fenrus.org> <20070727114637.GC11895@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: david@lang.hm Cc: linux-pm , LKML , Pavel Machek , Arjan van de Ven List-Id: linux-pm@vger.kernel.org On Sun, Jul 29, 2007 at 03:00:07PM -0700, david@lang.hm wrote: > yes it is, and each type of device is growing it's own, incompatible, > interfaces for controlling things like this. I was aiming to do two > things. Anything playing with power management needs to be aware of the limitations of the hardware. Many devices have reduced functionality when in reduced power states, and it's vital that the caller be aware of that. There's no way to express that information in a consistent way because the limitations vary widely between different types of device. So, given that software will need to be aware of the different special cases for different types of hardware, there's very little cost to each of them exposing a different interface. -- Matthew Garrett | mjg59@srcf.ucam.org