From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id EF06B1A0F74 for ; Sat, 21 Feb 2015 18:14:57 +1100 (AEDT) Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 21 Feb 2015 07:14:53 -0000 Message-ID: <54E83051.9080107@fr.ibm.com> Date: Sat, 21 Feb 2015 08:14:25 +0100 From: Cedric Le Goater MIME-Version: 1.0 To: Guenter Roeck Subject: Re: [RFC PATCH 0/3] hwmon: (ibmpowernv) add DTS support References: <1423117857-32759-1-git-send-email-clg@fr.ibm.com> <1424444857-13805-1-git-send-email-clg@fr.ibm.com> <20150220165212.GE22752@roeck-us.net> <54E795FA.1090005@fr.ibm.com> <54E7C8C7.40001@roeck-us.net> In-Reply-To: <54E7C8C7.40001@roeck-us.net> Content-Type: text/plain; charset=windows-1252 Cc: Stewart Smith , lm-sensors@lm-sensors.org, Neelesh Gupta , skiboot@lists.ozlabs.org, linuxppc-dev@lists.ozlabs.org, Jean Delvare List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/21/2015 12:52 AM, Guenter Roeck wrote: > On 02/20/2015 12:15 PM, Cedric Le Goater wrote: >> On 02/20/2015 05:52 PM, Guenter Roeck wrote: >>> On Fri, Feb 20, 2015 at 04:07:34PM +0100, Cédric Le Goater wrote: >>>> Hello ! >>>> >>>> These patches rework the ibmpowernv driver to support the new device >>>> tree as proposed by this patchset on the skiboot mailing list : >>>> >>>> https://lists.ozlabs.org/pipermail/skiboot/2015-February/000457.html >>>> >>>> They are based on Linux 3.19 and were tested on IBM Power and Open Power >>>> systems running trusty. >>>> >>>> The main issue is that the new device tree is incompatible with the >>>> previous ibmpowernv drivers. The consequence is no powernv sensors >>>> on systems with such a opal/linux configuration. >>>> >>> I don't think that would be acceptable. There must be lots of such >>> systems out there. Why does it have to be incompatible ? >>> Can't it support both the old and new versions ? >> >> I should have provided more explanation in the Linux patchset. Sorry >> for that. Here is the rationale behind this brutal code change. >> >> The initial ibmpowernv driver was designed in the early days of the >> powernv platform and the device tree it is using to expose the sensors >> has some limitations that makes it difficult to add new ones. The current >> layout of the device tree is also tightly coupled to IBM Power systems >> and their service processor (FSP). Open Power systems are different and >> need a different solution. >> >> It is to get more sensors out the P8 (and there are quite a few) that >> the OPAL patchset [1] proposes a new device tree. On the Linux side, it >> feels simpler to make a jump forward and break the compatibility than >> to maintain multiple branches of code just to keep alive an early v1 >> of the ibmpowernv driver. >> > > Would it possibly be appropriate to write a different driver for the new > device tree ? Sure. That is an option. There are no conflicts between the trees so we can live with two drivers using the same sensors/ root node. With time we will deprecate the initial one. Is that the preferred option ? How would we name the new driver ? 1. powernv 2. powernv-hwmon 3. openpowernv 4. ibmpowernv2 Thanks, C. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cedric Le Goater Date: Sat, 21 Feb 2015 07:14:25 +0000 Subject: Re: [lm-sensors] [RFC PATCH 0/3] hwmon: (ibmpowernv) add DTS support Message-Id: <54E83051.9080107@fr.ibm.com> List-Id: References: <1423117857-32759-1-git-send-email-clg@fr.ibm.com> <1424444857-13805-1-git-send-email-clg@fr.ibm.com> <20150220165212.GE22752@roeck-us.net> <54E795FA.1090005@fr.ibm.com> <54E7C8C7.40001@roeck-us.net> In-Reply-To: <54E7C8C7.40001@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Guenter Roeck Cc: Stewart Smith , lm-sensors@lm-sensors.org, Neelesh Gupta , skiboot@lists.ozlabs.org, linuxppc-dev@lists.ozlabs.org, Jean Delvare On 02/21/2015 12:52 AM, Guenter Roeck wrote: > On 02/20/2015 12:15 PM, Cedric Le Goater wrote: >> On 02/20/2015 05:52 PM, Guenter Roeck wrote: >>> On Fri, Feb 20, 2015 at 04:07:34PM +0100, C=E9dric Le Goater wrote: >>>> Hello ! >>>> >>>> These patches rework the ibmpowernv driver to support the new device >>>> tree as proposed by this patchset on the skiboot mailing list : >>>> >>>> https://lists.ozlabs.org/pipermail/skiboot/2015-February/000457.html >>>> >>>> They are based on Linux 3.19 and were tested on IBM Power and Open Pow= er >>>> systems running trusty. >>>> >>>> The main issue is that the new device tree is incompatible with the >>>> previous ibmpowernv drivers. The consequence is no powernv sensors >>>> on systems with such a opal/linux configuration. >>>> >>> I don't think that would be acceptable. There must be lots of such >>> systems out there. Why does it have to be incompatible ? >>> Can't it support both the old and new versions ? >> >> I should have provided more explanation in the Linux patchset. Sorry >> for that. Here is the rationale behind this brutal code change. >> >> The initial ibmpowernv driver was designed in the early days of the >> powernv platform and the device tree it is using to expose the sensors >> has some limitations that makes it difficult to add new ones. The current >> layout of the device tree is also tightly coupled to IBM Power systems >> and their service processor (FSP). Open Power systems are different and >> need a different solution. >> >> It is to get more sensors out the P8 (and there are quite a few) that >> the OPAL patchset [1] proposes a new device tree. On the Linux side, it >> feels simpler to make a jump forward and break the compatibility than >> to maintain multiple branches of code just to keep alive an early v1 >> of the ibmpowernv driver. >> >=20 > Would it possibly be appropriate to write a different driver for the new > device tree ? Sure. That is an option.=20 There are no conflicts between the trees so we can live with two drivers=20 using the same sensors/ root node. With time we will deprecate the initial one. Is that the preferred option ? How would we name the new driver ?=20 1. powernv 2. powernv-hwmon 3. openpowernv 4. ibmpowernv2=20 Thanks, C. _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors