[SOLVED] failed to set system clock

Message

jopeto · Post by **jopeto** » Tue Jul 24, 2012 10:12 am

Hello,

I had a problem on my computer that when it was booting up, one of the messages showing was

hwclock: Cannot access the Hardware Clock via any known method
hwclock: use the --debug option to see th details of out serch for an access method
* Failed to set system clock

and when i typed the command

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date

The time which was displayed was not the correct one. So I followed the advice in this thread
http://forums.gentoo.org/viewtopic-p-68 ... 0db97586f8
and enabled

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Device Drivers -> Character devices -> <*> Generic /dev/rtc emulation 
 <*> Extended ETC operation

The error at boot time disappeared, however the time shown was still not the accurate one. So I also enabled

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Devide Drivers -> Real Time Clock -> PC-style 'CMOS'

as a module.

Now, the time shown using the "date" command after booting is the accurate one, however when I boot up I get the same error message that the system clock failed to be set. I find that very strange. Should I worry about this or just leave it as it is?

Thanks a lot.

Hypnos · Post by **Hypnos** » Tue Jul 24, 2012 11:55 am

Try the following kernel options (assuming you are on a PC platforml):

Processor type and features -.> High Resolution Timer Support

Device drivers -> Real Time Clock -> Set system time from RTC on startup and resume

You shouldn't need emulation once HPET is enabled ...

jopeto · Post by **jopeto** » Wed Jul 25, 2012 2:42 pm

I tried enabling Device Drivers -> Character devices -> HPET, but when I ran make && make module_install I got

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make: *** No rule to make target `module_install'.  Stop.

Is that an error or not?

gorkypl · Post by **gorkypl** » Wed Jul 25, 2012 3:11 pm

modules_install

Hypnos · Post by **Hypnos** » Wed Jul 25, 2012 3:11 pm

It's modules_install , with an s

jopeto · Post by **jopeto** » Wed Jul 25, 2012 4:25 pm

Stupid me... I'll try again.

eccerr0r · Post by **eccerr0r** » Wed Jul 25, 2012 7:21 pm

About these clock problems, I've seen some PC hardware that doesn't like the "PC CMOS RTC" option even... Still for some reason the time gets set somehow...

Anyway, it would be nice when posting about clock problems, to also post what hardware you're using, especially if not PC-based. Seems there are some somewhat nonstandard clock systems out there even on PCs. One would hope they all are compatible with the original PC/AT CMOS real time clock but...that's yet another legacy device...

jopeto · Post by **jopeto** » Fri Jul 27, 2012 1:06 pm

Sorry for the late reply, but I was traveling with no access to internet.

So I enabled in the kernel Device Drivers -> Character devices -> HPET and now the error on boot up disappeared, however when I type the "date" command, I get the wrong time again... Strange, it looks like that I can either make the error disappear, or the date to be correct, but not the two at the same time...

I am using amd64 version of Gentoo on an Intel B950 cpu. Please let me know if you need any more info on the hardware.

When you say "About these clock problems, I've seen some PC hardware that doesn't like the "PC CMOS RTC" option even." does that mean that I need to disable that from the kernel or enable a different option?

Thanks.

eccerr0r · Post by **eccerr0r** » Fri Jul 27, 2012 1:35 pm

I'm not entirely sure myself, I'm just worried that we're solving an issue for a non-PC platform (like Macintosh) machine with PC assumptions... Then again there are PC compatible platforms that don't exactly work all the time... Unsure of the "correct" settings, very motherboard dependent...

jopeto · Post by **jopeto** » Fri Jul 27, 2012 7:02 pm

OK, so I set my hardware clock using the bios setup and now everything is working fine. I guess that my system is set up so that the system clock is changed according to the hardware clock and not the other way around. I guess I'll have to look into commands how to make which clock primary and secondary.

Hypnos · Post by **Hypnos** » Sat Jul 28, 2012 12:17 am

jopeto wrote:[..] I guess that my system is set up so that the system clock is changed according to the hardware clock and not the other way around. [...]

The usual practice is on bootup to retrieve the time from the hardware clock, and then on shutdown to set the hardware clock from the system clock. This way the time is preserved while the system is not operating.

You can change this behavior in /etc/conf.d/hwclock .

jopeto · Post by **jopeto** » Mon Jul 30, 2012 7:35 am

Thanks!

jopeto · Post by **jopeto** » Wed Aug 01, 2012 7:38 am

OK, I think part of my troubles was that I didn't have ntp installed. Here's the wiki on this:
http://en.gentoo-wiki.com/wiki/NTP

I found out about ntp from the comments in the file /etc/conf.d/hwclock

eccerr0r · Post by **eccerr0r** » Wed Aug 01, 2012 8:00 am

odd, it shouldn't be mandatory to have ntp running. Machines with no network access would be stuck...

Hmm... I should look into this some more the next time I run into this....Weird...

jopeto · Post by **jopeto** » Wed Aug 01, 2012 1:20 pm

Sorry, I guess I wasn't clear enough in my previous post. Having ntp is not mandatory but it is recommended. Since I have internet access, I decided to install it and set it up.

The problem which I guess I had was that in /etc/conf.d/hwclock I had setting the hardware clock to the software clock on log out disabled. I guess things should work when enabling it even without ntp.

Sorry once again for the confusion.

Hypnos · Post by **Hypnos** » Wed Aug 01, 2012 1:22 pm

If you are satisfied with the function of your system clock, please add "[SOLVED]" to the thread title (by editing the first post) in case someone else has the same problem.