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 …

@matanh Modify kernel configure to modify CONFIG_RTC_HCTOSYS_DEVICE to rtc0 to build new kernel for it. Thanks

Looks like regression for r35.1 Will update once get solution for it.

Modify the /lib/udev/rules.d/50-udev-default.rules to below for the problem. SUBSYSTEM=="rtc", ATTR{hctosys}=="0", SYMLINK+="rtc" SUBSYSTEM=="rtc", KERNEL=="rtc0", SYMLINK+="rtc", OPTIONS+="link_priority=-100"

Hi @ShaneCCC Confirmed your method. Seems It’s a workaround that use RTC0 as system date’s RTC source. But RTC1 still got a wrong date after reboot: [Screenshot from 2022-10-27] Does Nvidia have any plan to fix RTC1’s issue? Will the issue be fixed in Jetpack5.1?

Hi, Do you have a battery connected in your setup?

Also, if you are asking if “RTC1” will get fixed, then the answer is no. It won’t get fixed. Only RTC0 can keep the time across boot.

Hi @WayneWWW I have done the same experiment on the same AGX Xavier developer kit with L4T 32.7.1. RTC0 and RTC1 both worked fine. So I don’t think the battery is the problem. You can see the following images about the experiment result. I am surprised the RTC1 won’t get fixed. So the tegra_de…

Hi Share Sorry. About previous method from you. [image] The system date still is wrong. I missed to compare the system time and RTC0. You can see there are still not consistent. [image] So we don’t have any workaround or solution for the RTC issue. Can you help to solve it?

Do you reboot the system or remove the power?

Please set the date time by sudo date -s “2022/11/04 15:30” RTC time by “sudo hwclock -w /dev/rtc*” the reboot to verify.

Hi @ShaneCCC Confirmed your workaround can’t work. Because the workaround is only create an symbolic /dev/rtc to /dev/rtc0. That only can make timedatectl show a correct RTC time from rtc0. But the system time sync mechanism is done by kernel driver. You can check the dmesg to see it. Provid…

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

Robotics & Edge Computing Jetson Systems Jetson AGX Xavier

barryhung November 10, 2022, 7:14am 17

We also have the same problem , can’t keep RTC data after reboot.

RTC clock issue on on NX devkit JP5.0.2

Boot has wrong time 5 times out of 24

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

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