From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40mgsM4lZBzF1QL for ; Thu, 17 May 2018 16:10:47 +1000 (AEST) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w4H604Ea011084 for ; Thu, 17 May 2018 02:10:44 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2j14308eg1-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 17 May 2018 02:10:44 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 17 May 2018 07:10:42 +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> 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: Thu, 17 May 2018 11:40:35 +0530 MIME-Version: 1.0 In-Reply-To: <20180515150205.GA29321@roeck-us.net> Content-Type: text/plain; charset=windows-1252 Message-Id: <2ceb6b30-60b7-d985-ee0d-6c5784eda273@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 > 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 >