Comment 5 for bug 1945940

A system relies on realtime clock (RTC) to do a cold boot to start automatically. There can be some possibilities:

1. RTC hardware isn't stable enough (related to motherboard and / or BIOS)
2. RTC wake-up time expired before system shut down, and alarm was triggered too early.

One can use command "rtcwake" to verify RTC.

For example, I use "sudo rtcwake -m mem -s 15" to put my system to s3 and wake it up after 15 seconds. One can use "sudo rtcwake -m off -s 120" to power off a system and wake it up after 120 seconds