From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755385AbaGaB1X (ORCPT ); Wed, 30 Jul 2014 21:27:23 -0400 Received: from gate.crashing.org ([63.228.1.57]:50105 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750897AbaGaB1W (ORCPT ); Wed, 30 Jul 2014 21:27:22 -0400 Message-ID: <1406770020.4935.166.camel@pasglop> Subject: Re: [PATCH 0/3] therm_windtunnel doesn't work properly on PowerMac G4 From: Benjamin Herrenschmidt To: kreijack@inwind.it Cc: Jean Delvare , LKML Date: Thu, 31 Jul 2014 11:27:00 +1000 In-Reply-To: <53D95AAF.6030309@inwind.it> References: <53D95AAF.6030309@inwind.it> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2014-07-30 at 22:50 +0200, Goffredo Baroncelli wrote: > Hi All, > > I am writing to you Jean and Benjamin because it seem that both > worked on these items. > > On a PowerMac G4 I noticed that between the kernel v3.2 and v3.14 I lost > the fan management. > > I found on internet other references to this kind of problem [2] Patches look good, thanks. Jean do you want to apply them or should I ? Cheers, Ben. > > **How reproduce: > - booting with the kernel 3.2, the fan is "quite" silent. > The module therm_windtunnel is loaded and in the log there are > lines like: > > [ 1342.614956] CPU-temp: 58.7 C, Case: 33.7 C, Fan: 5 (tuned +0) > [ 1390.637793] CPU-temp: 58.6 C, Case: 33.6 C, Fan: 5 > > I had also access to the temperature via the sysfs files: > /sys/devices/temperature/case_temperature > /sys/devices/temperature/cpu_temperature > > > - booting with the kernel 3.14, the fan is very loud. The module > therm_windtunnel is not loaded. In the log there aren't any message > related to the temperature. The sysfs entries don't exist. > > > ** Analysis > In these Apple machines the module i2c-powermac requires the > i2c drivers provided by the module therm_windtunnel. > > Between the kernel v3.2 and v3.14 [1] some patches changed the > driver name requested by the i2c-powermac module, > so the therm_windtunnel modules is not instantiated anymore. > > > ** Proposed solution > In the following emails I sent you three patches to solve this > problem (tested on my PowerMac G4) > > 1) change the driver name > therm_ds1775 -> MAC,ds1775 > therm_adm1030 -> MAC,adm1030 > so the i2c driver are instantiated by i2c-powermac > > 2) remove the (unused) method do_attach from the i2c-driver > 3) add two parameters to the therm_windtunnel module > to control the kernel log message > > The patch 1) solve the problem. The patch 2) is a small cleanup. > The patch 3) allow a better control of the log in dmesg. > > Could you be so kindly to apply these patches ? > > BR > G.Baroncelli > > > > [1] I think that the guilty commit is > > commit 81e5d8646ff6bf323dddcf172aa3cef84468fa12 > Author: Benjamin Herrenschmidt > Date: Wed Apr 18 22:16:42 2012 +0000 > > i2c/powermac: Register i2c devices from device-tree > > This causes i2c-powermac to register i2c devices exposed in the > device-tree, enabling new-style probing of devices. > > Note that we prefix the IDs with "MAC," in order to prevent the > generic drivers from matching. This is done on purpose as we only > want drivers specifically tested/designed to operate on powermacs > to match. > > This removes the special case we had for the AMS driver, and updates > the driver's match table instead. > > Signed-off-by: Benjamin Herrenschmidt > > [2] There is the debian bug #741663 which highlight the same problem. In > the bug discussion there is a patch like the my ones. > > See also > https://lists.ozlabs.org/pipermail/linuxppc-dev/2012-July/099561.html > > > >