From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [RFD] How to tell ACPI drivers what the target sleep state is (was: Re: [PATCH 1/2] acpi choose sleep state help) Date: Thu, 21 Jun 2007 07:48:47 -0700 Message-ID: <200706210748.48781.david-b@pacbell.net> References: <1182220394.14837.9.camel@sli10-conroe.sh.intel.com> <200706210004.03544.david-b@pacbell.net> <200706211442.41140.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from smtp117.sbc.mail.sp1.yahoo.com ([69.147.64.90]:28010 "HELO smtp117.sbc.mail.sp1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752856AbXFUPha (ORCPT ); Thu, 21 Jun 2007 11:37:30 -0400 In-Reply-To: <200706211442.41140.rjw@sisk.pl> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: Shaohua Li , linux acpi , Len Brown , Pavel Machek , pm list On Thursday 21 June 2007, Rafael J. Wysocki wrote: > The issue at hand is that some device drivers may need to know what t= he > target sleep state of the system will be when their .suspend() routin= es are > being executed. =A0Currently, there's no means of passing that inform= ation to the > drivers and my question is how to do this. Actually what they need to know is some *attribute* of that state. They really don't care what the state is. The $SUBJECT patch isn't driver code ... it's for platform hooks that expose attributes to the drivers. Specifically, it's ACPI code, talking to drivers that must run on non-ACPI systems. Any driver that thinks it needs to understand anything about ACPI states is sadly broken. Remember also that the Linux "states" (in /sys/power/state) are an inadequate representation of what most hardware can do. Common hardware can support a lot more low power sleep modes than the two states Linux currently defines ... a limitation inherited from first APM, and them more recently ACPI, which doesn't fit embedded systems well at all. - Dave - To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html