[ltp] Massive clock drift on new thinkpad R32

[David Peterson]

Hi All,

Further to my posts of a couple of days ago, I have narrowed down the 
source of the bug. It appears to be the apmd package (yep, I was rather 
surprised too!). As I mentioned, I am using debian (testing), so 
strictly speaking this could mean the apmd package or one of its 
dependencies, eg libapm, etc. In any case, when I disable the apm 
modules in /etc/modules.conf and restart, the problem disappears ...

I will lodge a bug report with debian, as well as testing the latest 
(debian/unstable) version of apmd (and deps) to see if the problem still 
persists.

Thanks again to all those who responded for your useful help and tips.

Regards,

David Peterson



Tod Harter wrote:

>On Friday 22 November 2002 02:16 am, David Peterson wrote:
>  
>
>>Hi Todd,
>>
>>When I think of changes I have made, only a couple of things readily
>>come to mind:
>>
>>- upgraded from 2.4.18 kernel to 2.4.19 kernel using the debian kernel
>>images
>>- installed a sound driver (the i810_audio module, which also loads the
>>soundcore module and ac97_codec module)
>>
>>As you can see from the following post, the system is "losing time"
>>
>>    
>>
>Well, theoretically either of those changes might be involved. Technically 
>what happens is that once Linux kernel is up and running it reads the RTC to 
>find out what time it is and sets the 'system time'. From then on every 10 
>milliseconds or so the timer chip should assert a 'clock-tick' interrupt, at 
>which point the kernel updates system time. If there is a hardware or 
>software problem with that interrupt then naturally it would cause the 
>kernel's concept of time to drift. Anything running in 'ring 0' (kernel or 
>most device drivers) could easily be the culprit in missed clock-ticks, its 
>just that GENERALLY the consequences of such problems rapidly become 
>catastrophic, so such a bug is rare to find in a production release of any 
>kind. 
>
>Given the steps you say you've taken to correct the problem I'm not sure what 
>other advice I'd have for you. It is always possible its a hardware problem 
>and XP simply manages to run OK by sheer chance (slightly different way it 
>accesses hardware, etc.). It kind of feels like one of those (reinstall from 
>scratch and hope it goes away) kind of problems (I know, I sound like MS tech 
>support, ah well).
>
>  
>