From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754907AbaHGSQR (ORCPT ); Thu, 7 Aug 2014 14:16:17 -0400 Received: from mail-pd0-f169.google.com ([209.85.192.169]:44431 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751116AbaHGSQP (ORCPT ); Thu, 7 Aug 2014 14:16:15 -0400 Date: Thu, 7 Aug 2014 11:16:11 -0700 From: Guenter Roeck To: Goffredo Baroncelli Cc: Jean Delvare , Benjamin Herrenschmidt , LKML Subject: Re: [PATCH 5/5] Export the temperatures via hwmon Message-ID: <20140807181611.GA7679@roeck-us.net> References: <1407359103-6012-1-git-send-email-kreijack@inwind.it> <1407359103-6012-6-git-send-email-kreijack@inwind.it> <20140806231803.GA5643@roeck-us.net> <53E31694.8050107@gmail.com> <53E31AB0.6070604@roeck-us.net> <20140807085235.2c0e63dd@endymion.delvare> <53E32C77.5000804@roeck-us.net> <53E3BC48.4020304@inwind.it> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53E3BC48.4020304@inwind.it> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 07, 2014 at 07:50:00PM +0200, Goffredo Baroncelli wrote: > On 08/07/2014 09:36 AM, Guenter Roeck wrote: > > On 08/06/2014 11:52 PM, Jean Delvare wrote: > >> Hi Guenter, > >> > >> On Wed, 06 Aug 2014 23:20:32 -0700, Guenter Roeck wrote: > >>> Patch 4/5 is "Return the fan speed via sysfs: /sys/devices/temperature/fan_level". > >>> > >>> So you are saying that returning the fan speed with a non-hwmon attribute works, > >>> but returning it with a hwmon attribute doesn't ? Not really sure if I understand > >>> your logic. Either fan_level doesn't return the fan speed (or an abstraction of it), > >>> or something in your line of argument is inconsistent. > >> > >> fan_level is a fan speed _control_ value, like pwm1. It is not a fan > >> speed monitoring value. > >> > > Ah, ok. The patch description doesn't seem to match, though. > > And why not export it as pwm1, if that is what it is ? > > > > Guenter > > > > > > the exported fan_level value is a coefficient near proportional to the speed [*]; > so it is not the speed nor the pwm. > I tried to read the pwm/speed value, but when I did it, every 5/6 seconds the > fan seemed to stop for 1s, then the speed raised.... So I stopped the test. > > These patches (the first two) solved a real issue: with the last kernels this > driver doesn't work at all, and the fan go to maximum speed (very loud !) > The other three are an improvement. > > When (if) these patches will be accepted I want to write another solution, > but definitely not now. And even if it would work for me, it is very likely > that will be accepted because nobody is able to test it on all hardware. > Might have been easier to just drop all this non-standard code and instantiate the adm1030 using the adm1031 driver instead. Guenter