Hardware RTC device is deregistered immediately after detection

Solution Verified - Updated -

Issue

The hardware clock is not operable with the hwclock utility. The kernel ring buffer contains the following messages:

WARNING: at arch/x86/kernel/rtc.c:125 mach_get_cmos_time+0x175/0x190() (Not tainted)
rtc_cmos 00:0a: RTC can wake from S4
rtc_cmos 00:0a: rtc core: registered rtc_cmos as rtc0
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

which means that the RTC device was detected, but then was immediately deregistered.

Environment

  • Red Hat Enterprise Linux
  • RTC device, that does not support 24-hr BCD mode

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Current Customers and Partners

Log in for full access

Log In

New to Red Hat?

Learn more about Red Hat subscriptions

Using a Red Hat product through a public cloud?

How to access this content