Messages in this thread | | | Subject | Re: [PATCH 0/3] Add support to disable sensor groups in P9 | From | Guenter Roeck <> | Date | Thu, 17 May 2018 05:38:25 -0700 |
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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
>> 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 >> > >
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