From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH, RFC] [1/3] Generic in-kernel AC status Date: Tue, 14 Feb 2006 21:17:30 +0100 Message-ID: <200602142117.31232.rjw@sisk.pl> References: <20060208125753.GA25562@srcf.ucam.org> <20060210121913.GA4974@elf.ucw.cz> <43F216FE.7050101@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from ogre.sisk.pl ([217.79.144.158]:9354 "EHLO ogre.sisk.pl") by vger.kernel.org with ESMTP id S1422784AbWBNUQs convert rfc822-to-8bit (ORCPT ); Tue, 14 Feb 2006 15:16:48 -0500 In-Reply-To: <43F216FE.7050101@suse.de> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Thomas Renninger Cc: Pavel Machek , Stefan Seyfried , Matthew Garrett , linux-pm@lists.osdl.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org On Tuesday 14 February 2006 18:44, Thomas Renninger wrote: > Pavel Machek wrote: > > On P=E1 10-02-06 09:06:43, Stefan Seyfried wrote: > >> On Wed, Feb 08, 2006 at 12:57:53PM +0000, Matthew Garrett wrote: > >>> The included patch adds support for power management methods to r= egister=20 > >>> callbacks in order to allow drivers to check if the system is on = AC or=20 > >>> not. Following patches add support to ACPI and APM. Feedback welc= ome. > >> Ok. Maybe i am not seeing the point. But why do we need this in th= e kernel? > >> Can't we handles this easily in userspace? > >=20 > > Some kernel parts need to now: for example powernow-k8: some > > frequencies are not allowed when you are running off battery. [Just > > now it is solved by not allowing those frequencies at all unless AC= PI > > is available; quite an ugly solution.] > >=20 > Allowed CPUfreqs are exported via _PPC. > This is why a lot hardware sends an ac_adapter and a processor event > when (un)plugging ac adapter. > Limiting cpufreq already works nice that way. >=20 > AMD64 laptops are booting with lower freqs per default until they are > pushed up, so there shouldn't be anything critical? This is not true as far as my box is concerned (Asus L5D). It starts w= ith the _highest_ clock available. > For the brightness part, I don't see any "laptop is going to explode" > issue. > I always hated the brightness going down when I unplugged ac on M$ Currently I have the same problem on Linux, but I don't know the soluti= on (yet). Any hints? :-) Rafael - 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