Jetson Nano eMMC POM_5V_IN/POM_5V_GPU mismatch?

Autonomous Machines Jetson & Embedded Systems Jetson Nano
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#1

Hi,

I am working on a product based on the Jetson Nano. I have a rev B02 developer kit with a rev B00 eMMC module attached to it, and I am using L4T 32.4.4. I am working on some power consumption and thermal testing. Part of this is exercising the CPU and GPU, and looking at the resultant power figures from the INA3221. When I have the GPU turned off, the POM_5V_IN channel reads 0, while the POM_5V_GPU channel reads “normal” values. When I start exercising the GPU, the POM_5V_IN channel starts reading normal values, which increase as I increase the load on the GPU.

The DTS file where the channels for the INA3221 are defined is /sources/hardware/nvidia/platform/t210/porg/kernel-dts/porg-platforms/tegra210-porg-powermon-p3448-0000-a00.dtsi as far as I can tell, even for the rev B00 eMMC board. This file has the channels defined as they show up in sysfs. I haven’t tested this with my older SD-card based kit to see if the channel order is correct for that board, since I do not want to spend time making my test/dev environment work on the SD card once again.

Finally to the question: should the POM_5V_GPU and POM_5V_IN channels should be swapped in the rev B00 DTS?

Thanks,

Chris Richardson

#6

Hi cjwti,

We’re trying to reproduce the issue on the reference platforms.
Please stay tuned.

#8

hello cjwti,

the power monitor channel of 5V is swapped with VDD_GPU; you’ll need to update device tree to B01 dts for verification.
thanks

#9

Hi JerryChang and kayccc,

Thanks for the responses guys. I appreciate you looking at this. JerryChang, I am fine with updating the device tree and swapping those channels, but I do notice there is no rev b00 dts file for the ina3221x power monitor device. I searched the entire /hardware folder now and found the overlay file which swaps the channels (tegra210-porg-plugin-manager.dtsi). I removed this file from being included in the main device tree file quite a while back because the imx219 nodes present there were interfering with the camera I am using. I didn’t realize at the time that these ‘plugins’ might be more important.

So my next question, besides the changes for swapping the channels on the ina3221x node, are there other changes in tegra210-porg-plugin-manager.dtsi that I must include? From a quick read through, it does seem likely, but I would like to avoid including all the imx219 stuff and having to fight against that to get my camera to work.

Thanks,

Chris Richardson

#10

hello cjwti,

instead of excluding the tegra210-porg-plugin-manager.dtsi from the main device tree.
suggest you to use the command, i.e. /delete-property/ in your own device tree to remove those nodes that interfering with your device.
thanks

#11

Hey JerryChang,

Thanks for the information on that. I re-included the plugin-manager.dtsi file and used delete-node to remove some nodes that were previously causing problems. Now I see the correct INA3221 channel names on my device. One thing I noticed along the way is that several nodes in the plugin-manager.dtsi file are named “fragement”. This didn’t affect my work and I suppose it is just a typo.

Thanks again for your help!

Chris Richardson