Jetson Nano RTC wake immediately wakes


We are designing a device to reside in a vehicle and be powered through the car battery. We are attempting to reduce the power consumption as much as possible when the device is not in use. I have read in other forum topics that the command sudo rtcwake -m mem -s 60 should put the nano into a low power mode for 60 seconds. However, when running this command the device turns off for roughly 1 second and immediately comes back up. This is the output from the system:

$ sudo rtcwake -m mem -s 60
rtcwake: assuming RTC uses UTC...
rtcwake: wakeup from "mem" using /dev/rtc0 at Tue Nov 17 20:27:01 2020
rtcwake: write error

Any information on why this command doesn’t work as described in the other forum post would be very helpful. I can provide any other supplemental information needed.

Thank you!

Not sure as I have no Nano for checking, but you may try this.

Which software release are you using?

We are using Jetpack 4.4 and L4T 32.4.3. We have modified the kernel and device tree to add support for 2 i2c devices, but there are no other changes.

Hi benx0aoa,

We tried on JP-4.4.1 (r32.4.4), there are no issue.

$ sudo rtcwake -m mem -s 60
rtcwake: assuming RTC uses UTC ...
rtcwake: wakeup from "mem" using /dev/rtc0 at Thu Nov 19 02:54:44 2020

—> After 60 seconds, rtcwake.