From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH 2/2] Add a passive cooling trip point if the firmware doesn't define one Date: Thu, 15 May 2008 03:24:31 +0100 Message-ID: <20080515022431.GA15085@srcf.ucam.org> References: <20080514010000.GB21608@srcf.ucam.org> <20080514010300.GC21608@srcf.ucam.org> <20080514010820.GD21608@srcf.ucam.org> <200805132330.20159.lenb@kernel.org> <20080514093304.GB28678@srcf.ucam.org> <1210812916.2929.6.camel@rzhang-crestline.sh.intel.com> <20080515010426.GA13927@srcf.ucam.org> <1210814699.2929.10.camel@rzhang-crestline.sh.intel.com> <20080515015831.GA14829@srcf.ucam.org> <1210817739.2929.24.camel@rzhang-crestline.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:51502 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbYEOCY4 (ORCPT ); Wed, 14 May 2008 22:24:56 -0400 Content-Disposition: inline In-Reply-To: <1210817739.2929.24.camel@rzhang-crestline.sh.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhang Rui Cc: linux-acpi , Len Brown On Thu, May 15, 2008 at 10:15:39AM +0800, Zhang Rui wrote: > On Thu, 2008-05-15 at 02:58 +0100, Matthew Garrett wrote: > > I'll modify my patch so it uses the devices in a _TZD package if they're > > present. > > > Hmm, ACPI thermal zone doesn't know how to throttle the devices in a > _TZD package, so I don't think we can use the _TZD devices. If they have a _TZD, it's presumably because they need cooling. If the kernel isn't going to be able to do that, what happens if the userspace daemon crashes or fails to start for some reason? The alternative is to leave it as it is currently in my patch. If the userspace daemon starts, it disables the ACPI control and will handle it itself. If it doesn't start, the kernel does the only thing it can - reduce the speed of the CPU. If there are no plans to add hooks for the drivers to be throttled by the kernel, then I'd argue that this is the right thing to do. -- Matthew Garrett | mjg59@srcf.ucam.org