Date and time wrong on TX2

[vantai]

We have changed the date and time of the Jetson TX2. However, whenever we reboot the device, the date and time go back to its own (2021) rather then continue with which we have set up, even though the Automatic Date & Time switch set to off.

What should we do to fix this issue?

[KevinFFF]

Hi vantai,

Are you using the devkit or custom board for TX2?
What’s your Jetpack version in use?

How did you configure the date and time? (from command or GUI?)

[vantai]

Hi Kevin,

We use devkit TX2; Jetpack version is 4.6.1; We changed the date and time from GUI.

Thanks!

[DaveYYY]

Hi,

you have to switch to rtc0 for the system to keep time after rebooting.
Some posts FYI:

RTC can't hold time the after system rebooted in L4T 35.1

Hi NV RTC can’t hold the after system rebooted in L4T 35.1 version AGX Xavier developer kit I confirmed it worked fine in L4T 32.71 with same developer kit. Here is my steps: (1) Set system date and RTC time and read it back. [Screenshot from 2022-10-25 11-19-51] (2) System reboot. Then read system date and RTC time again. The red block of the following image showed that RTC time became a wrong value. [Screenshot from 2022-10-25 11-20-25]

AGX Orin: rtc0 vs rtc1

There are 2 real time clocks on Orin: rtc0 and rtc1. The rtc0 can be supported by the battery, but rtc1 cannot. The kernel however is configured to sync time with rtc1, which causes the time to be incorrect at the boot, until it is synced with network time. Are there specific reasons for kernel using rtc1? Are there any known issues with re-configuring the kernel to use rtc0?

[vantai]

Hi Dave,
How can we switch to rtc0?

[DaveYYY]

You can either change the udev rule or change the kernel config and build the kernel again:

AGX Orin: rtc0 vs rtc1

Hi, rtc0 is supported by other power management IC, while rtc1 is inside the Tegra SoC itself. We set rtc1 as default because it runs on TSC (Time Stamp Counter), and has higher accuracy. You may config the udev rules as follow if you want to use rtc0: inside /lib/udev/rules.d/50-udev-default.rules SUBSYSTEM==“rtc”, ATTR{hctosys}==“0”, SYMLINK+=“rtc” SUBSYSTEM==“rtc”, KERNEL==“rtc0”, SYMLINK+=“rtc”, OPTIONS+=“link_priority=-100” Or change CONFIG_RTC_HCTOSYS_DEVICE in kernel config and bu…