Sudo halt makes it hot?

Hello,

I just bought jetson nano. I was ssh to the nano and did some install and when done and ready for shutdown, i executed sudo halt

And when i came back later (1 hour?) the heatsink got very hot. I suppose the sudo halt does shutdown the nano no? I am using the barrel jack (3A), rj45. No keyboard, no mouse or another devices.

The jetson nano is a older version with 1 camera connector.

Cheers

Hi,

May I know why you just run sudo halt but not sudo shutdown? Halt would halt the OS and stop all the CPU but it does not send command to disable the main power.

Bad habit? I use halt when i run raspberry pi and never notice this issue…
Normally, the power is on when the OS is running, but heatsink is not hot at all. So what is the difference when OS is off but power still on? Bad design on this board?

Cheers

I think probably because the software thermal throttling mechanism is turned off when you use halt.
Let me discuss some further detail with our internal team. It sounds a problem.

1 Like

Hi Oai,

We suggest you to use "sudo halt --poweroff” or “sudo poweroff” instead of your current command.
The difference is here.

I would say maybe raspberry pi does not have such power mechanism so halt and shutdown is equal. However, things are different on Jetson Nano.

Hi Wayne,

What did your team say about why the heat sink is very hot? I mean when use the Nano, the heatsink is just warm. But when halt, it gets really hot. From the serverfault.com : Halting involves stopping all CPUs on the system.

So, no CPU, no workload, what cause the heat sink to be hot?

It’s like you turn off your car, but the gas is still gone next morning :)

Hi Oai,

You are right. Actually we are still investigating this issue.
Please try to use "sudo halt --poweroff” at this moment.

Hi oai,

It turns out halt on Nano does not turns off any CPUs and just suspend the system… that is why it still gets hot after.

Hej Wayne,

But when the system is on and running or idle, it’s just warm. So if you suspend the system, the temperature should be same as idle.

It sounds like a design flaw, no? What about the new jetson nano? Did you check this issue on that board?

Hi Oai,

I think the behavior of halt is different from SC7 deep sleep mode. Actually, according to our discussion internally, the function of “sudo halt” is never verified on our side.
I would suggest you could use SC7 suspend mode instead of halt if you want to put device into sleep and use shutdown or halt -p to poweroff the device.

Hey,

Sure i will use the other alternative so turn off the Nano. I am just curious why the Nano get hot when halt. I mean what makes the board (very) hot (like CPU 100%). If Nvidia is not interest to investigate this issue than this will be my first and last jetson nano. I have never seen any SoC or computer behave like this. I really like the jetson nano but this design flaw…Nope!

Cheers

Hi Oai,

We are still checking this issue internally, but cannot give you a good explanation yet. I believe this is still a software issue but not hardware. Once we know what is going on, I will share with you.
Before we have conclusion, maybe you could try to use the commands above first.

Thanks.