Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758755AbZJGIRK (ORCPT ); Wed, 7 Oct 2009 04:17:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758723AbZJGIRJ (ORCPT ); Wed, 7 Oct 2009 04:17:09 -0400 Received: from mail-yx0-f173.google.com ([209.85.210.173]:61531 "EHLO mail-yx0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758725AbZJGIRG (ORCPT ); Wed, 7 Oct 2009 04:17:06 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=GvlWCn6QRTaAZROi7e2lbAFbBotZVk7nEB2hQ0YMDnsfGUqvSrYYpfYIUywszyU2AK EGOL4uY/zcXWfutQ1r+KY1ZHU3UHKmoh8+qXHMT6K6SN3yiTM5Lih57jjVwsISneqYlY zv25+zV3Y7hhLwF1P/Hqyukji/Mdm3elHvNNs= MIME-Version: 1.0 In-Reply-To: <20091007073121.GA31245@elf.ucw.cz> References: <20090812005532.GA31003@srcf.ucam.org> <20090814163233.GC1626@ucw.cz> <20090816074008.GA11624@1wt.eu> <4ACB59E2.3000600@amd.com> <20091007073121.GA31245@elf.ucw.cz> Date: Wed, 7 Oct 2009 18:16:29 +1000 Message-ID: <21d7e9970910070116h6cf4e472i309537e9b4bb1e08@mail.gmail.com> Subject: Re: [PATCH][ACPI] AC/DC notifier From: Dave Airlie To: Pavel Machek Cc: "Tippett, Matthew" , Willy Tarreau , Matthew Garrett , "Langsdorf, Mark" , lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, "Li, Samuel" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1616 Lines: 38 On Wed, Oct 7, 2009 at 5:31 PM, Pavel Machek wrote: > On Tue 2009-10-06 10:53:22, Tippett, Matthew wrote: >> (Resending as text-only - sorry) >> >> Bringing this item back up again. >> >> I am not suggesting that the application of any particular policy >> appears within the kernel or userspace or a secondary policy engine. >> In general I am also against codifying policy within drivers. >> >> I am interested seeing the ACPI notifier mechanism expanded to allow >> AC/DC state changes propagate to other kernel drivers without requiring >> a userspace in between. >> >> I can continue to come up with real scenarios that would possibly >> require kernel-to-kernel notification, but would rather focus this >> discussion of the pure technical issues associated with adding the >> notifier to the AC/DC ACPI subsystem. > > Please do. So far you did not show valid use for such notifier. > > (Ok, I know of one. Old amd64 notebooks had cpufreq scaling enabled, > with battery unable to supply enough current to feed the CPU at > highest cpufreq setting. At that point, scaling cpufreq down at unplug > is correctness issue, and AC/DC notifier in kernel makes > sense.) > > So... what do you want to use it for? I'm not sure we have a open driver use case for this, if not I suggest we remove it and only add it when a user is added to the kernel. Dave. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/