Bug 759071

Summary:	time is not correct after reboot
Product:	[Fedora] Fedora	Reporter:	Marcela Mašláňová <mmaslano>
Component:	systemd	Assignee:	systemd-maint
Status:	CLOSED DUPLICATE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	16	CC:	johannbg, lpoetter, metherid, mlichvar, mschmidt, notting, plautrba, systemd-maint
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-09-18 16:07:33 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Marcela Mašláňová 2011-12-01 11:20:51 UTC

Description of problem:
After reboot of computer time isn't set correctly.

Version-Release number of selected component (if applicable):
systemd-37-3.fc16.x86_64
chrony-1.26-3.20110831gitb088b7.fc16.x86_64

How reproducible:
After every reboot.

Steps to Reproduce:
1. time is correct, set by chronyd for my time zone
2. switch off computer in 9:58
3. switch on with(out) network
4. time is set to 18:59
  
Actual results:
Without network synchronization is time set to wrong time. I didn't find explanation.  Could it be that I see time, which is set by last call of "hwclock --systohc"?


Expected results:
Correct time, everytime.

Additional info:
This is not bug of chronyd, because it "fixes" the time value. I wonder what people without network will do.

Comment 1 Michal Schmidt 2011-12-01 13:26:12 UTC

(In reply to comment #0)
> Could it be that I see time, which is set by last call of
> "hwclock --systohc"?

I don't know. Does running that command change what you're seeing?

Comment 2 Marcela Mašláňová 2011-12-05 07:53:12 UTC

(In reply to comment #1)
> (In reply to comment #0)
> > Could it be that I see time, which is set by last call of
> > "hwclock --systohc"?
> 
> I don't know. Does running that command change what you're seeing?

No, it's not related to when I run hwclock.

Comment 3 Michal Schmidt 2012-06-07 15:41:55 UTC

When ntp is used, the kernel writes the current time to to the RTC every 11 minutes, but it only corrects for errors within a 30-minute window. It won't fix the hours. That may explain what you're seeing.

But if it's really it, I'd expect that "hwclock --systohc" run before shutdown to result in the correct time after new boot.

Comment 4 Kay Sievers 2012-09-17 19:18:44 UTC

Michal, do you know which kernel code does the minutes-update-only?

I can't find that limitation in the code. We should decide what to fix here,
if we optionally let the kernel do a full sync instead of minutes only, or
ask the ntp implementations to solve that for us.

But first I need to find the code in the kernel, that does that. :)

Comment 5 Michal Schmidt 2012-09-18 13:40:33 UTC

It's mach_set_rtc_mmss() in arch/x86/kernel/rtc.c

Comment 6 Kay Sievers 2012-09-18 16:07:33 UTC

Merging with #816752 which is the same issue. This one is older, but the
other one has more information, and the discussion took place in the
other bug. Thanks!

*** This bug has been marked as a duplicate of bug 816752 ***