Re: Quanta requests to create a repo in OpenBMC github

From: Benjamin Fair <benjaminfair@google.com>
To: Patrick Williams <patrick@stwcx.xyz>
Cc: "Josh Lehan" <krellan@google.com>,
	"openbmc@lists.ozlabs.org" <openbmc@lists.ozlabs.org>,
	"Brad Bishop" <bradleyb@fuzziesquirrel.com>,
	"Fran Hsu (徐誌謙)" <Fran.Hsu@quantatw.com>
Subject: Re: Quanta requests to create a repo in OpenBMC github
Date: Thu, 17 Sep 2020 16:35:44 -0700	[thread overview]
Message-ID: <CADKL2t5npwwBs6ecKAqscJ8=BoakpwDNMjuSiZOSXTkCNcLryA@mail.gmail.com> (raw)
In-Reply-To: <20200917152912.GG6152@heinlein>

On Thu, 17 Sep 2020 at 08:29, Patrick Williams <patrick@stwcx.xyz> wrote:
>
> Would someone mind giving a 1-2 sentence explaination of what "sensor
> margin values" are?  I'm certainly not a thermal control expert.

This daemon is intended to be used in combination with
phosphor-pid-control. You define a configuration file with two
sections: sensors and zones.

Sensors have a D-Bus path to read from along with a target temperature
and some other parameters. The daemon subtracks the current
temperature from the target temperature to get the "margin". A smaller
margin means the temperature is closer to the limit.

Zones group sensors together and look for the worst (lowest) margin
value within that group. This value is then exported for use in
phosphor-pid-control.

>
> I don't care if there are multiple implementations of similar
> functionality, but there is also work going on for a repository called
> 'phosphor-virtual-sensors'.  What little I could understand of
> read-margin-temp's role seems to somewhat overlap with that effort.

It may be possible to implement this using the functionality provided
by phosphor-virtual-sensors, but the resulting configuration would
likely be complicated and difficult to maintain. Margin calculation is
a common enough use case that I think it's worth having a dedicated
service.

>
> On Wed, Sep 16, 2020 at 10:37:14PM -0700, Josh Lehan wrote:
> > Yay, this is great to see. I have some bug fixes to read-margin-temp and
> > was just wondering how to contribute them. I'm really hoping this makes it
> > into OpenBMC. It's the perfect preprocessor for phosphor-pid-control, I
> > have found.
> >
> > Josh
> >
> > Josh Lehan | Software Engineer | krellan@google.com | +1 650-733-8941
> >
> >
> >
> > On Wed, Sep 16, 2020 at 7:15 PM Benjamin Fair <benjaminfair@google.com>
> > wrote:
> >
> > > On Wed, 16 Sep 2020 at 06:31, Fran Hsu (徐誌謙) <Fran.Hsu@quantatw.com>
> > > wrote:
> > > >
> > > > Hi Brad,
> > > >         This is Fran from Quanta Computer.
> > > > Quanta OpenBMC team would like to share some useful tools to the OpenBMC
> > > community.
> > > > Such as the read-margin-temp daemon (
> > > https://github.com/quanta-bmc/read-margin-temp), we are using this daemon
> > > to fill sensor margin value to PID to do fan control.
> > >
> > > read-margin-temp seems useful and widely applicable enough that I
> > > think it's worth having a dedicated repo for it.
> > >
> > > The quanta-misc repo could possibly be used for smaller, more
> > > Quanta-specific things.
> > >
> > > >
> > > > We would like to have a repo named "quanta-misc" under the OpenBMC
> > > github.
> > > >
> > > > Here is the maintainer list:
> > > > M:  Benjamin Fair <benjaminfair@google.com> <benjaminfair!>
> > > > M:  Brandon Kim <brandonkim@google.com> <brandonk!>
> > > > M:  Fran Hsu <fran.hsu@quantatw.com> <franhsu!>
> > > > M:  George Hung <george.hung@quantatw.com> <ghung!>
> > > > M:  Buddy Huang <buddy.huang@quantatw.com> <buddyhunag!>
> > > >
> > > > Thank you.
> > > > Fran Hsu
> > > > E-Mail : Fran.Hsu@QuantaTW.com
> > > > Tel: +886-3-327-2345 Ext: 16935 <+886%203%20327%202345>
> > > >
> > > >
> > >
>
> --
> Patrick Williams