Re: [PATCH v2] hwmon: Driver for temperature sensors on SATA drives

[Guenter Roeck]

On 1/12/20 5:45 AM, Gabriel C wrote:
> Am So., 12. Jan. 2020 um 14:07 Uhr schrieb Guenter Roeck <linux@xxxxxxxxxxxx>:
> > On 1/12/20 4:07 AM, Linus Walleij wrote:
> > > On Sun, Jan 12, 2020 at 1:03 PM Gabriel C <nix.or.die@xxxxxxxxx> wrote:
> > > > Am So., 12. Jan. 2020 um 12:22 Uhr schrieb Linus Walleij
> > > > <linus.walleij@xxxxxxxxxx>:
> > > > > On Sun, Jan 12, 2020 at 12:18 PM Gabriel C <nix.or.die@xxxxxxxxx> wrote:
> > > > >
> > > > > > What I've noticed however is the nvme temperature low/high values on
> > > > > > the Sensors X are strange here.
> > > > > (...)
> > > > > > Sensor 1:     +27.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)
> > > > > > Sensor 2:     +29.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)
> > > > > (...)
> > > > > > Sensor 1:     +23.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)
> > > > > > Sensor 2:     +25.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)
> > > > >
> > > > > That doesn't look strange to me. It seems like reasonable defaults
> > > > > from the firmware if either it doesn't really log the min/max temperatures
> > > > > or hasn't been through a cycle of updating these yet. Just set both
> > > > > to absolute min/max temperatures possible.
> > > >
> > > > Ok I'll check that.
> > > >
> > > > Do you mean by setting the temperatures to use a lmsensors config?
> > > > Or is there a way to set these with a nvme command?
> > >
> > > Not that I know of.
> > >
> > > The min/max are the minumum and maximum temperatures the
> > > device has experienced during this power-on cycle.
> >
> > No, that would be lowest/highest. The above are (or should be) per-sensor
> > setpoints. The default for those is typically the absolute minimum /
> > maximum of the supported range.
> >
> > Some SATA drives report the lowest/highest temperatures experienced
> > since power cycle, like here.
> >
> > drivetemp-scsi-5-0
> > Adapter: SCSI adapter
> > temp1:        +23.0ÂC  (low  =  +0.0ÂC, high = +60.0ÂC)
> >                          (crit low = -41.0ÂC, crit = +85.0ÂC)
> >                          (lowest = +20.0ÂC, highest = +31.0ÂC)
>
> The SATA temperatures are fine and reported like this here too, just
> the nvme ones are strange.
>
> drivetemp-scsi-4-0
> Adapter: SCSI adapter
> temp1:        +28.0ÂC  (low  =  +1.0ÂC, high = +61.0ÂC)
>                        (crit low =  +2.0ÂC, crit = +60.0ÂC)
>                        (lowest = +16.0ÂC, highest = +31.0ÂC)
>
> drivetemp-scsi-12-0
> Adapter: SCSI adapter
> temp1:        +29.0ÂC  (low  =  +1.0ÂC, high = +61.0ÂC)
>                        (crit low =  +2.0ÂC, crit = +60.0ÂC)
>                        (lowest = +18.0ÂC, highest = +32.0ÂC)
>
> and so on.
>
> Btw, where I can find the code does these calculations?

Not sure if that is what you are looking for, but the nvme hardware
monitoring driver is at drivers/nvme/host/hwmon.c, the SATA hardware
monitoring driver is at drivers/hwmon/drivetemp.c.

The limits on nvme drives are configurable.

root@server:/sys/class/hwmon# sensors nvme-pci-0100
nvme-pci-0100
Adapter: PCI adapter
Composite:    +40.9ÂC  (low  = -273.1ÂC, high = +84.8ÂC)
                       (crit = +84.8ÂC)
Sensor 1:     +40.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)
Sensor 2:     +43.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)

root@server:/sys/class/hwmon# echo 0 > hwmon1/temp2_min
root@server:/sys/class/hwmon# echo 100000 > hwmon1/temp2_max

root@server:/sys/class/hwmon# sensors nvme-pci-0100
nvme-pci-0100
Adapter: PCI adapter
Composite:    +38.9ÂC  (low  = -273.1ÂC, high = +84.8ÂC)
                       (crit = +84.8ÂC)
Sensor 1:     +38.9ÂC  (low  =  -0.1ÂC, high = +99.8ÂC)
Sensor 2:     +42.9ÂC  (low  = -273.1ÂC, high = +65261.8ÂC)

If you dislike the defaults, just configure whatever you think is
appropriate for your system.

Thanks,
Guenter