VDDIN_OC_LIMIT cannot be set

[chhg82]

Hi,
I'm using kirkstone/JetPack5.1.2 on a Xavier NX device. When setting the power mode sudo nvpmodel -m 8 an error occurs that apparently VDDIN_OC_LIMIT cannot be set.
If I comment out the following in /etc/nvpmodel.conf under power model definitions it works:

#VDDIN_OC_LIMIT WARN 4000
#VDDIN_OC_LIMIT CRIT 5000

The limits are set here:

< PARAM TYPE=HWMON NAME=VDDIN_OC_LIMIT >
WARN /sys/devices/platform/c250000.i2c/i2c-7/7-0040/hwmon curr1_max
CRIT /sys/devices/platform/c250000.i2c/i2c-7/7-0040/hwmon curr1_crit

It seems that hwmon is missing on my NX:

XavierNX:~$ ll /sys/devices/platform/c250000.i2c/i2c-7/7-0040/
total 0
-r--r--r-- 1 root root 4096 Mar 19 15:36 modalias
-r--r--r-- 1 root root 4096 Mar 19 15:19 name
lrwxrwxrwx 1 root root 0 Mar 19 15:36 of_node -> ../../../../../firmware/devicetree/base/i2c@c250000/ina3221@40
drwxr-xr-x 2 root root 0 Mar 19 15:29 power
lrwxrwxrwx 1 root root 0 Apr 28 2022 subsystem -> ../../../../../bus/i2c
-rw-r--r-- 1 root root 4096 Apr 28 2022 uevent

Which kernel module loads hwmon and what could be the problem that it is not present for me?
Thank you!

[chhg82]

I found out that if I generate linux-tegra with CONFIG_SENSORS_INA3221=y and thus compile the power state chipset driver into the kernel, then hwmon is linked and nvpmodel -m 8 runs! Why is CONFIG_SENSORS_INA3221=m (by default) not working as kernel module and what is the best practice?

[chhg82]

My custom machine is based on jetson-xavier-nx-devkit-emmc.conf, so as you say, MACHINE_EXTRA_RRECOMMENDS and KERNEL_MODULE_AUTOLOAD are already set correctly. However, in tegra-nvpmodel-base.bbappend an RDEPENDS:${PN} += "kernel-module-ina3221" seems to be necessary for the module to be loaded. What do you think about that?

[madisongh]

Kernel module/driver dependencies use RRECOMMENDS rather than RDEPENDS; otherwise, if the driver is built into the kernel (y instead of m), the dependency will fail.

If you're building an image that excludes packagegroup-machine-base (for example, core-image-minimal or something based off that recipe), you won't get the MACHINE_EXTRA_RRECOMMENDS packages - that's the packagegroup that includes them.

[chhg82]

Yes thanks, RRECOMMENDS does it too!

You're right, I'm using core-image-minimal. I was wondering because bitbake -e myimage has the following output:

MACHINE_EXTRA_RRECOMMENDS="kernel-module-nvgpu kernel-module-snd-hda-tegra kernel-module-snd-hda-codec-hdmi kernel-module-ina3221 kernel-module-tegra-bpmp-thermal kernel-module-spi-tegra114 kernel-module-ahci kernel-module-max77620-thermal kernel-module-pwm-fan kernel-module-tegra-udrm kernel-module-rtk-btusb kernel-module-rtl8822ce tegra-firmware-rtl8822"

...but at runtime only the nvgpu and nvmap modules are loaded (now also ina3221).

Wouldn't it make sense to integrate it into tegra-nvpmodel-base.bb in meta-tegra? Could there be any other potentially necessary RRECOMMENDS that I haven't noticed yet?

[madisongh]

Yes, pretty much everything listed in the MACHINE_EXTRA_RRECOMMENDS and MACHINE_EXTRA_RDPENDS variables. Really, I don't recommend using core-image-minimal as the starting point for anything where you actually want to use the features of the hardware - as the Yocto documentation states, that recipe just gets you the bare minimum to boot the system. core-image-base is a better base to work from.