Red Hat Bugzilla – Bug 442711
hwclock cannot access the Hardware Clock
Last modified: 2008-04-18 01:53:16 EDT
Description of problem:
hwclock can not get a hold on hardware clock. This causes ntpd to fail also, I
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. do "hwclock --show" as root
hwclock --rtc=/dev/rtc0 --debug --show
hwclock from util-linux-ng 2.13.1
hwclock: Open of /dev/rtc0 failed, errno=16: Device or resource busy.
No usable clock interface found.
Cannot access the Hardware Clock via any known method.
Show/set system time correctly.
[root@whipper ~]# cat /sys/class/rtc/rtc0/dev
[root@whipper ~]# ls -lZ /dev/rtc0
crw-r--r-- root root system_u:object_r:clock_device_t:s0 /dev/rtc0
[root@whipper ~]# ls -l /dev/rtc0
crw-r--r-- 1 root root 254, 0 2008-04-16 19:56 /dev/rtc0
Created attachment 302590 [details]
dmidecode, lspci -vvv, cpuinfo, lsmod
Why do you need to use the option --rtc? Without this option hwclock(8) is
trying to open other clock devices.
It would be nice to check logs for AVC denial messages too.
Today I received new kernel via updates. I don't know if it was that, but
hwclock started working.
Kzak: No, I did not see AVC denials and it was the same without --rtc, I just
tried to force it for the right clock if it would not have found it otherwise.
Works now, so the bug can be closed.