Gigabyte GA-B650M-D3HP working & lm_sensors fixed

[JustinS-B]

Arch Linux, Kernel Version 6.13.1-arch1-1
Gigabyte Technology Co., Ltd. B650M D3HP motherboard

TLDR:
lm_sensors all working on GA-B650M-D3HP with it87 running Arch Linux.
Installed it87-dkms-git and edited lm_sensors.service

Original errors and problems
Running sensors-detect gives No, No, No except for finding an unknown chip with ID 0x8689 on a Gigabyte GA-B650M-D3HP motherboard running an AMD Ryzen 7 8700G cpu.

Trying family `ITE'...                                      Yes
Found unknown chip with ID 0x8689
Probing for Super-I/O at 0x4e/0x4f

Trying to start lm_sensors.service gives the following error

lm_sensors.service: Referenced but unset environment variable evaluates to an empty string: BUS_MODULES, HWMON_MODULES

Fix: for Arch Linux, just install AUR/it87-dkms-git

However, there are a couple of nice gotcha's that can cause you problems.

Unless you have /etc/sensors.d/GA-B650M-D3HP.conf in place, you can't customise and of the sensor temperature settings. More importantly, unless you run sensors -s after each boot, none of your settings are applied. This is usually done by lm_sensors.service, but because the sensors-detect script doesn't like it87 chips, it failed to set the $BUS_MODULES and $HWMON_MODULES environmental variables and then didn't enable lm_sensors.service. However, it's easy to fix it all. Normally, all the lm_sensors scripts have a really clever way of enumerating and discovering the kernel modules that you need to read to get the temperature and fan data from the sensors. Alas, they just don't work for us because we have an it87 type chip. Thankfully, we know exactly how to load it & which specific options we need to use to get it all to work perfectly, so we can hard code that into the service file.

sudo systemctl edit --full lm_sensors.service


[Unit]
Description=Initialize hardware monitoring sensors

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/sbin/modprobe it87 force_id=0x8689 ignore_resource_conflict=1
ExecStart=/usr/bin/sensors -s
ExecStop=/sbin/modprobe -r it87

[Install]
WantedBy=multi-user.target

Don't forget to do a systemctl daemon-reload and then enable it with systemctl enable lm_sensors.service

Copy this conf file into /etc/sensors.d/GA-B650M-D3HP.conf and reboot to check that everything works as expected

# Gigabyte B650M D3HP GA-B650M-D3HP
#
# dmi: Board Manufacturer: Gigabyte Technology Co., Ltd.            
# dmi: Board Product Name: B650M D3HP
# dmi: BIOS Version: F22b
#
# 2025-02-07 JustinS-B
# Label mapping is mostly the same as for IT8686 on GA-B450M-DS3H and GA-B550M-DS3H
# https://github.com/frankcrawford/it87/blob/master/Sensors%20configs/GA-B450M-DS3H.conf
# But I added "nvme-pci-*", "gigabyte_wmi-virtual-*", and chip "acpitz-acpi-0" for completeness.

# Gigabyte B550M-DS3H
#
# dmi: Board Manufacturer: Gigabyte Technology Co., Ltd.            
# dmi: Board Product Name: B550<-DS3H
# dmi: BIOS Version: unknown
#
# 2023-09-24 DymOK93
# Label mapping is the same as for IT8686 on GA-B450M-DS3H

# Copied from 
# https://raw.githubusercontent.com/frankcrawford/it87/refs/heads/master/Sensors%20configs/GA-B550M-DS3H.conf

chip "it8689-*"
    label in0 "VCORE"
    label in1 "+3.3V"
        compute in1 @ * 1.65, @ / 1.65
    label in2 "+12.0V"
        compute in2 @ * 6, @ / 6
    label in3 "+5.0V"
        compute in3 @ * 2.5, @ / 2.5
    label in4 "VSOC"
    label in5 "VDDP"
    label in6 "DRAM"
    label in7 "3VSB"
    label in8 "VBAT"
    label fan1 "CPU Fan"
        set fan1_min  0
    label fan2 "SYS Fan 1"
    label fan3 "SYS Fan 2"
#    label fan4 "SYS Fan 3_PUMP"
#    label fan5 "CPU_OPT"
    label temp1 "System"
        set temp1_min  0.00
        set temp1_max  127.00
    label temp2 "Chipset"
        set temp2_min  0.00
        set temp2_max  127.00
    label temp3 "CPU"
        set temp3_min  0.00
        set temp3_max  127.00
    label temp4 "PCIe x16"
        set temp4_min  0.00
        set temp4_max  127.00
    label temp5 "VRM"
        set temp5_min  0.00
        set temp5_max  127.00
    label temp6 "VSoC"
        set temp6_min  0.00
        set temp6_max  127.00
    label intrusion0 "Intrusion"

# Note: The NAND Flash is always 8-10°C hotter than the Controller & the Composite readings
#       because NAND Flash runs hot...
chip "nvme-pci-*"

label temp1 "NVME_Composite"
  set temp1_min  0.5
  set temp1_max  127.50

label temp2 "NVME_Controller"
  set temp2_min  0.5
  set temp2_max  127.50

label temp3 "NVME_NAND_Flash"
  set temp3_min  0.5
  set temp3_max  127.50

# These are the same as temp sensors from chip "it8689-*" so you can safely ignore them if you want to
chip "gigabyte_wmi-virtual-*"

    label temp1 "System"
    label temp2 "Chipset"
    label temp3 "CPU"
    label temp4 "PCIe x16"
    label temp5 "VRM"
    label temp6 "VSoC"

#    ignore temp1
#    ignore temp2
#    ignore temp3
#    ignore temp4
#    ignore temp5
#    ignore temp6

chip "acpitz-acpi-0"
    label temp1 "CPU Die"

# For the record, "k10temp-pci-00c3" is a pseudo-temperature (see below),
# so it has been left "as is"
#
# info copied from
# https://www.kernel.org/doc/html/latest/hwmon/k10temp.html
#
# "Tctl is the processor temperature control value, used by the platform to 
# control cooling systems. Tctl is a non-physical temperature on an
# arbitrary scale measured in degrees. It does _not_ represent an actual
# physical temperature like die or case temperature. Instead, it specifies
# the processor temperature relative to the point at which the system must
# supply the maximum cooling for the processor's specified maximum case
# temperature and maximum thermal power dissipation."
#

For the record, the sensord.service logging daemon has an unlisted dependency of extra/rrdtool without which it won't run.