Re: [EXT] Re: OpenBMC Sensors

[Aaron Williams <awilliams@marvell.com>]

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 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@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@gmail.com> wrote:
> > > > On Thu, Jan 24, 2019 at 5:13 PM Aaron Williams <awilliams@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-architecture.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)