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

Guenter Roeck
2020-01-12T15:26:44Z

On 1/12/20 5:45 AM, Gabriel C wrote:
> Am So., 12. Jan. 2020 um 14:07 Uhr schrieb Guenter Roeck <linux@roeck-us.net>:
>>
>> On 1/12/20 4:07 AM, Linus Walleij wrote:
>>> On Sun, Jan 12, 2020 at 1:03 PM Gabriel C <nix.or.die@gmail.com> wrote:
>>>> Am So., 12. Jan. 2020 um 12:22 Uhr schrieb Linus Walleij
>>>> <linus.walleij@linaro.org>:
>>>>>
>>>>> On Sun, Jan 12, 2020 at 12:18 PM Gabriel C <nix.or.die@gmail.com> wrote:
>>>>>
>>>>>> What I've noticed however is the nvme temperature low/high values on
>>>>>> the Sensors X are strange here.
>>>>> (...)
>>>>>> Sensor 1: +27.9°C (low = -273.1°C, high = +65261.8°C)
>>>>>> Sensor 2: +29.9°C (low = -273.1°C, high = +65261.8°C)
>>>>> (...)
>>>>>> Sensor 1: +23.9°C (low = -273.1°C, high = +65261.8°C)
>>>>>> Sensor 2: +25.9°C (low = -273.1°C, high = +65261.8°C)
>>>>>
>>>>> 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: +23.0°C (low = +0.0°C, high = +60.0°C)
>> (crit low = -41.0°C, crit = +85.0°C)
>> (lowest = +20.0°C, highest = +31.0°C)
>>
>
> 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: +28.0°C (low = +1.0°C, high = +61.0°C)
> (crit low = +2.0°C, crit = +60.0°C)
> (lowest = +16.0°C, highest = +31.0°C)
>
> drivetemp-scsi-12-0
> Adapter: SCSI adapter
> temp1: +29.0°C (low = +1.0°C, high = +61.0°C)
> (crit low = +2.0°C, crit = +60.0°C)
> (lowest = +18.0°C, highest = +32.0°C)
>
> 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: +40.9°C (low = -273.1°C, high = +84.8°C)
(crit = +84.8°C)
Sensor 1: +40.9°C (low = -273.1°C, high = +65261.8°C)
Sensor 2: +43.9°C (low = -273.1°C, high = +65261.8°C)

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: +38.9°C (low = -273.1°C, high = +84.8°C)
(crit = +84.8°C)
Sensor 1: +38.9°C (low = -0.1°C, high = +99.8°C)
Sensor 2: +42.9°C (low = -273.1°C, high = +65261.8°C)

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

Thanks,
Guenter