Hi Ross,

I have a version of your timer patch (io_apic.c) for kernel 2.6.1.  It is 
attached.  I have been monitoring a problem with it.  It seems that with the 
patch, I gain 1 seconds time over 10 minutes (roughly).  So I gain about 2-3 
mintues a day.  I haven't taken exact measurements, but I know it ends up about 
20 minutes difference after a week.  This is not good, which would require 
resetting the time often.  

I tried the 2.6.1 kernel without the timer patch.  The timer is now back in PIC 
mode, and interrupt 7 has the old noise.  Synched the time with my watch.  At 
first, I noticed no gain in time over 10 minutes.  However the next day, I found
it gained 1-2 seconds.  Now it is about 7 seconds ahead a few days later now.  
This is much better.

So I'm left to thinking, the patch does two things, maybe one thing right, and 
one possibly very wrong:

1) It does place the timer in APIC mode.
2) But the timer seems to be fed extra interrupts, maybe the same that is found 
on irq 7 without the patch (is this possible?)

I remember someone making a comment which might explain the issue:
http://marc.theaimsgroup.com/?l=linux-kernel&m=107098440019588&w=2

I don't think the patch was much different now than it was then.  So I think 
there is something wrong with setting up the timer this way.  I don't know if 
you worked something out with Maciej.  I don't know much about interrupt 
controller programming so...  if maybe you can explain to me anything I'm
missing.  For now I've dropped the patch.


Jesse


PS:  I have run with disconnect on, and without your ack patch since I got that 
surpise BIOS update.  No lockups have occurred in the past month, since that.  So the disconnect problem is a BIOS bug.  (Shuttle has not responded)

PSS:  CC me, I'm not subscribed right now.