From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:39956 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751281AbeEREEH (ORCPT ); Fri, 18 May 2018 00:04:07 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w4I43vrU096485 for ; Fri, 18 May 2018 00:04:06 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0b-001b2d01.pphosted.com with ESMTP id 2j1nd3kvp4-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 18 May 2018 00:04:06 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 18 May 2018 05:04:04 +0100 Subject: Re: [PATCH 0/3] Add support to disable sensor groups in P9 To: Guenter Roeck References: <1521716075-807-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> <20180515150205.GA29321@roeck-us.net> <2ceb6b30-60b7-d985-ee0d-6c5784eda273@linux.vnet.ibm.com> <56bba97b-c6ee-e7a1-136c-a2236437484a@roeck-us.net> Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, stewart@linux.vnet.ibm.com From: Shilpasri G Bhat Date: Fri, 18 May 2018 09:33:57 +0530 MIME-Version: 1.0 In-Reply-To: <56bba97b-c6ee-e7a1-136c-a2236437484a@roeck-us.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org On 05/17/2018 06:08 PM, Guenter Roeck wrote: > On 05/16/2018 11:10 PM, Shilpasri G Bhat wrote: >> >> >> On 05/15/2018 08:32 PM, Guenter Roeck wrote: >>> On Thu, Mar 22, 2018 at 04:24:32PM +0530, Shilpasri G Bhat wrote: >>>> This patch series adds support to enable/disable OCC based >>>> inband-sensor groups at runtime. The environmental sensor groups are >>>> managed in HWMON and the remaining platform specific sensor groups are >>>> managed in /sys/firmware/opal. >>>> >>>> The firmware changes required for this patch is posted below: >>>> https://lists.ozlabs.org/pipermail/skiboot/2018-March/010812.html >>>> >>> >>> Sorry for not getting back earlier. This is a tough one. >>> >> >> Thanks for the reply. I have tried to answer your questions according to my >> understanding below: >> >>> Key problem is that you are changing the ABI with those new attributes. >>> On top of that, the attributes _do_ make some sense (many chips support >>> enabling/disabling of individual sensors), suggesting that those or >>> similar attributes may or even should at some point be added to the ABI. >>> >>> At the same time, returning "0" as measurement values when sensors are >>> disabled does not seem like a good idea, since "0" is a perfectly valid >>> measurement, at least for most sensors. >> >> I agree. >> >>> >>> Given that, we need to have a discussion about adding _enable attributes to >>> the ABI >> >>> what is the scope, >> IIUC the scope should be RW and the attribute is defined for each supported >> sensor group >> > > That is _your_ need. I am not aware of any other chip where a per-sensor group > attribute would make sense. The discussion we need has to extend beyond the need > of a single chip. > > Guenter > Is it okay if the ABI provides provision for both types of attribute power_enable and powerX_enable. And is it okay to decide which type of attribute to be used by the capability provided by the hwmon chip? - Shilpa >>> when should the attributes exist and when not, >> We control this currently via device-tree >> >>> do we want/need power_enable or powerX_enable or both, and so on), and >> We need power_enable right now >> >>> what to return if a sensor is disabled (such as -ENODATA). >> -ENODATA sounds good. >> >> Thanks and Regards, >> Shilpa >> >> Once we have an >>> agreement, we can continue with an implementation. >>> >>> Guenter >>> >>>> Shilpasri G Bhat (3): >>>> powernv:opal-sensor-groups: Add support to enable sensor groups >>>> hwmon: ibmpowernv: Add attributes to enable/disable sensor groups >>>> powernv: opal-sensor-groups: Add attributes to disable/enable sensors >>>> >>>> .../ABI/testing/sysfs-firmware-opal-sensor-groups | 34 ++++++ >>>> Documentation/hwmon/ibmpowernv | 31 ++++- >>>> arch/powerpc/include/asm/opal-api.h | 4 +- >>>> arch/powerpc/include/asm/opal.h | 2 + >>>> .../powerpc/platforms/powernv/opal-sensor-groups.c | 104 ++++++++++++----- >>>> arch/powerpc/platforms/powernv/opal-wrappers.S | 1 + >>>> drivers/hwmon/ibmpowernv.c | 127 >>>> +++++++++++++++++++-- >>>> 7 files changed, 265 insertions(+), 38 deletions(-) >>>> create mode 100644 >>>> Documentation/ABI/testing/sysfs-firmware-opal-sensor-groups >>>> >>>> -- >>>> 1.8.3.1 >>>> >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in >>>> the body of a message to majordomo@vger.kernel.org >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> >> >