From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH] ACPI: add "auto" to acpi_enforce_resources Date: Wed, 04 Feb 2009 09:37:51 +0100 Message-ID: <498953DF.5050306@redhat.com> References: <20090125210520.GA12963@dreamland.darkstar.lan> <200901291130.35434.trenn@suse.de> <68676e00901290716g1aabd6c0p1e5202fbdbc659a4@mail.gmail.com> <20090204060513.GA28321@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.redhat.com ([66.187.237.31]:57454 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751122AbZBDIee (ORCPT ); Wed, 4 Feb 2009 03:34:34 -0500 In-Reply-To: <20090204060513.GA28321@srcf.ucam.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: Len Brown , Luca Tettamanti , Thomas Renninger , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, khali@linux-fr.org Matthew Garrett wrote: > On Wed, Feb 04, 2009 at 12:52:06AM -0500, Len Brown wrote: > >> While it is slightly off-topic of the (I agree, real) >> technical issue here, note that polling is not "normal" on ACPI systems. >> [1] was on SuSE Linux 10.0, which on their own decided to >> over-ride the kernel and enable thermal zone polling by default. > > Checking the DSDTs I have to hand, it seems that polling is expected on > about 5% of systems via an explicit _TZP and on almost all machines via > _TSP. Even on systems where thermal notifications are provided, it's > still up to the OS to poll the zone to find the current temperature and > take appropriate action. There's still a window for native smbus drivers > to screw everything up. > Note that this not only applies to smbus devices but also to superio devices, in general these superio hwmon devices use 2 isa ports an index and a data one, image they mayhem which could happen if for example: native driver sets index acpi driver sets index acpi driver reads data native driver writes data (to a completely wrong register) We *really* need to be fixing this. Len, Matthew, what is you opinion of the proposed auto setting for acpi_enforce_resources, which is meant to mean strict on known problematic systems and lax on others? Not I'm not asking what you think of the code (yet) just what you think of the principle. If we can atleast all agree on this as a compromise not breaking hwmon on quite a few systems (the strict setting) while stile providing something safer then the current lax, then I'm sure we can hash out any code problems soon enough. Regards, Hans