[EXT] Re: OpenBMC Sensors

Matthew Barth msbarth at linux.ibm.com
Sat Feb 2 06:32:44 AEDT 2019


Aaron,

Another option would be to look at the use of phosphor-fan-presence. The 
meta-ibm, romulus and witherspoon machines, configure each app (fan 
control, presence, monitoring) and contain the recipes to install them.


On 2/1/19 12:04 PM, Vijay Khemka wrote:
> Aron,
> You may also want to look at dbus-sensors as well. This is another approach for sensors through dbus. You have to include entity manager for this approach.
> 
> Regards
> -Vijay
> 
> On 1/31/19, 9:18 PM, "openbmc on behalf of Aaron Williams" <openbmc-bounces+vijaykhemka=fb.com at lists.ozlabs.org on behalf of awilliams at marvell.com> wrote:
> 
>      Thanks,
>      
>      I think I know what I need to do, after looking at the config example and
>      other yaml examples I've found. My problem is I haven't been able to find any
>      example recipes and whatnot that use this (or maybe I'm looking at the wrong
>      things). I've looked at the various implementations but don't see anything
>      using this.
>      
>      -Aaron
>      
>      On Thursday, January 31, 2019 7:30:04 AM PST Patrick Venture wrote:
>      > On Wed, Jan 30, 2019 at 8:49 PM Emily Shaffer <emilyshaffer at google.com>
>      wrote:
>      > > Aaron,
>      > >
>      > > If it's complaining at build time it's what it says on the box - you
>      > > probably need to include the recipe which builds
>      > > phosphor-fans-sensor-inventory.
>      > >
>      > > Emily
>      > >
>      > > On Wed, Jan 30, 2019, 8:17 PM Aaron Williams <awilliams at marvell.com>
>      wrote:
>      > >> Hi Emily,
>      > >>
>      > >> I'm still not sure how to go about using this, I'm still fairly new to
>      > >> OpenBMC. It's complaing about nothing providing
>      > >> 'virtual/phosphor-fans-sensor- inventory'.  I included
>      > >> phosphor-pid-control as one of our dependencies.
>      > Per Emily, you'll need to implement a recipe that defines the PID
>      > inputs.  It sounds like you have two PID loops.  One is the
>      > temperature sensor, and that feeds the set-point for the fans, which
>      > are a second PID loop.  The idea being, the temperature pid loop
>      > attempts to maintain the temperature under (or over) some set-point,
>      > and it'll in turn try to get the fans to speed up when necessary.
>      >
>      > >> -Aaron
>      > >>
>      > >> On Wednesday, January 30, 2019 1:48:10 PM PST you wrote:
>      > >> > Great, best luck Aaron. Thanks!
>      > >> >
>      > >> > On Wed, Jan 30, 2019, 1:47 PM Aaron Williams <awilliams at marvell.com>
>      wrote:
>      > >> > > Hi Emily,
>      > >> > >
>      > >> > > Thank you, I will look into it. I don't think losing the sensors when
>      > >> > > we
>      > >> > > cut
>      > >> > > power to the host CPU will be much of an issue. I was just notified
>      > >> > > of a
>      > >> > > change to our CPLD that will allow the BMC to keep the sensors
>      > >> > > powered. At
>      > >> > > the
>      > >> > > moment, cutting power shuts of the power from the ATX power supply
>      > >> > > but now
>      >
>      > As far as the sensors when the try is powered down, that's pretty
>      > common.  The hwmon driver on the BMC will just be unable to read the
>      > values, and you can deal with that in phosphor-hwmon a couple ways.
>      > Phosphor-pid-control will go into fail-safe mode if it doesn't receive
>      > a sensor value frequently enough.  This mode would cause it to drive
>      > the fans to a pre-defined set-point per a configuration.
>      >
>      > >> > > I
>      > >> > > will have more fine-grained power control. Now I just have to figure
>      > >> > > out
>      > >> > > how
>      > >> > > to update the Lattice CPLD from the BMC... I found some code in the
>      > >> > > Facebook
>      > >> > > OpenBMC which hopefully I can port over.
>      > >> > >
>      > >> > > -Aaron
>      > >> > >
>      > >> > > On Wednesday, January 30, 2019 1:42:40 PM PST Emily Shaffer wrote:
>      > >> > > > Aaron, we use this daemon for local (to BMC) thermal control:
>      > >> > > > https://github.com/openbmc/phosphor-pid-control
>      > >> > > > Maybe you'll find it helpful.
>      > >> > > >
>      > >> > > > Although I'm not sure how to help you with losing sensors when the
>      > >> > > > host
>      > >> > > > powers down but the BMC is expected to continue to cool the tray.
>      > >> > > > Sounds
>      > >> > > > like an issue with the board design, unless I'm not understanding
>      > >> > > > what
>      > >> > > > you're saying.
>      > >> > > >
>      > >> > > > On Wed, Jan 30, 2019 at 1:28 PM Aaron Williams
>      > >> > > > <awilliams at marvell.com>
>      > >> > > >
>      > >> > > > wrote:
>      > >> > > > > Hi Emily,
>      > >> > > > >
>      > >> > > > > That's what I need the temperature for. We have two controllers,
>      > >> > > > > one
>      > >> > >
>      > >> > > that
>      > >> > >
>      > >> > > > > monitors the core temperature (a TI TMP421) and one that controls
>      > >> > > > > the
>      > >> > >
>      > >> > > fans
>      > >> > >
>      > >> > > > > (ADT7462). In order to maintain the thermal envelope the TMP421
>      > >> > > > > needs
>      > >> > >
>      > >> > > to
>      > >> > >
>      > >> > > > > be
>      > >> > > > > monitored to adjust the fan speed through the ADT7462.
>      > >> > > > >
>      > >> > > > > Further complicating things is the fact that these sensors
>      > >> > > > > disappear
>      > >> > >
>      > >> > > when
>      > >> > >
>      > >> > > > > the
>      > >> > > > > host is powered down.
>      > >> > > > >
>      > >> > > > > -Aaron
>      > >> > > > >
>      > >> > > > > On Wednesday, January 30, 2019 9:49:32 AM PST Emily Shaffer
>      wrote:
>      > >> > > > > > External Email
>      > >> > >
>      > >> > > ---------------------------------------------------------------------
>      > >> > > -
>      > >> > >
>      > >> > > > > > Hi Aaron,
>      > >> > > > > >
>      > >> > > > > > Note that you only really need to worry about sending the
>      > >> > > > > > temperature
>      > >> > > > > > via
>      > >> > > > > > IPMI if you want to send it somewhere besides the BMC.  If you
>      > >> > > > > > plan
>      > >> > >
>      > >> > > to
>      > >> > >
>      > >> > > > > > do
>      > >> > > > > > internal thermal control (BMC reads temperature, BMC adjusts
>      > >> > > > > > fans
>      > >> > > > > > accordingly) you probably don't need IPMI config and can get
>      > >> > > > > > away
>      > >> > >
>      > >> > > with
>      > >> > >
>      > >> > > > > > setting it up as far as DBus in the sensor architecture doc Lei
>      > >> > > > > > sent.
>      > >> > > > > >
>      > >> > > > > > Emily
>      > >> > > > > >
>      > >> > > > > > On Thu, Jan 24, 2019 at 1:27 AM Lei YU <mine260309 at gmail.com>
>      wrote:
>      > >> > > > > > > On Thu, Jan 24, 2019 at 5:13 PM Aaron Williams <
>      > >> > >
>      > >> > > awilliams at marvell.com>
>      > >> > >
>      > >> > > > > > > wrote:
>      > >> > > > > > > > I see how to set up the hwmon portion defining the devices
>      > >> > > > > > > > based
>      > >> > >
>      > >> > > on
>      > >> > >
>      > >> > > > > the
>      > >> > > > >
>      > >> > > > > > > device
>      > >> > > > > > >
>      > >> > > > > > > > tree, but I am unsure how to go about configuring the YAML
>      > >> > > > > > > > and
>      > >> > >
>      > >> > > other
>      > >> > >
>      > >> > > > > > > files for
>      > >> > > > > > >
>      > >> > > > > > > > this.
>      > >> > > > > > >
>      > >> > > > > > > For sensors' config, please refer to
>      > >> > > > > > > https://github.com/openbmc/docs/blob/master/sensor-architectu
>      > >> > > > > > > re.md
>      > >> > > > > > >
>      > >> > > > > > > And it looks you are looking for fan controls, then you could
>      > >> > >
>      > >> > > refer
>      > >> > > to:
>      > >> > >
>      > >> > > https://github.com/mine260309/openbmc-intro/blob/master/Porting_Guide
>      > >> > > .md#f
>      > >> > >
>      > >> > > > > > > ans
>      > >> > > > > > >
>      > >> > > > > > > (I really need to submit my porting guide to openbmc/docs)
>      
>      
>      
>      
>      
> 



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