Bug 274261

Summary:	drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
Product:	[Fedora] Fedora	Reporter:	Robert Scheck <redhat-bugzilla>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	8	CC:	dbranchini, triage
Target Milestone:	---
Target Release:	---
Hardware:	i686
OS:	All
Whiteboard:	bzcl34nup
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2008-07-27 14:38:20 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Robert Scheck 2007-09-02 02:01:27 UTC

Description of problem:
Dmesg output contains the line:

drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

In addition, ntp has to correct the clock very often and to re-sync more often 
now - IMHO this problem is related to this rtc thing.

Version-Release number of selected component (if applicable):
kernel-2.6.23-0.157.rc4.git2

How reproducible:
Every time for me.

Actual results:
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

Expected results:
No error and no such obvious results regarding ntp.

Comment 1 Chuck Ebbert 2007-09-07 15:03:34 UTC

rtc is not used for timekeeping. Check what clocksource you are using, in
/sys/devices/system/clocksource/clocksource0/current_clocksource.

Then try a different one from the list in available_clocksource:
# echo [put new name here] >current_clocksource

acpi_pm should give the most stable result.

Comment 2 Robert Scheck 2007-09-07 15:06:05 UTC

"tsc" is the current one. How is selected which clocksource gets used? Finally, 
shouldn't the rtc0 error get fixed?

Comment 3 Chuck Ebbert 2007-09-07 15:15:09 UTC

clocksource selection doesn't work as well as it should on some hardware. You
can add "clocksource=acpi_pm" to the kernel boot options if that one works better.

Comment 4 Bug Zapper 2008-04-04 13:44:09 UTC

Based on the date this bug was created, it appears to have been reported
during the development of Fedora 8. In order to refocus our efforts as
a project we are changing the version of this bug to '8'.

If this bug still exists in rawhide, please change the version back to
rawhide.
(If you're unable to change the bug's version, add a comment to the bug
and someone will change it for you.)

Thanks for your help and we apologize for the interruption.

The process we're following is outlined here:
http://fedoraproject.org/wiki/BugZappers/F9CleanUp

We will be following the process here:
http://fedoraproject.org/wiki/BugZappers/HouseKeeping to ensure this
doesn't happen again.

Comment 5 Robert Scheck 2008-07-27 14:38:20 UTC

Doesn't seem to show up with rawhide any longer.