[LinuxPPS] Linux 2.6.28 - serial time string jumps

[Heiko Gerstung]

OK, new day, new problem...

Warning: This might be a little bit offtopic i.r.t. linuxpps, but I have 
seen that you guys are dealing with bleeding edge versions of the 
kernel, linuxpps and ntp (just like me) and might have similar 
experiences...

I am trying to test the new kernel with Rodolfo's linuxpps patch against 
ntp-4.2.4p6 ... PPS now works reliably but what I see is that the time 
of my GPS string reference (parse driver) is sometimes jumping for 3-4 
ms, resulting in being called a bad ass falseticker by ntpd and striked 
out (x). This in turn leads to the PPS source being rejected and after a 
short while (I am dealing with 16s polling intervals) everything seems 
to kick back to normal ...

The same hardware performs good under 2.6.15.1 (the last kernel version 
I was working on), back then with the PPSLight patch from Ulrich Windl. 
While I assume that PPS is working great here, I wonder if anyone has 
experienced jumps and latency issues on their serial ports with 2.6.28?

I know that I had some successful tests with 2.6.24 but I wanted to use 
a more recent kernel ...

Regards,
 Heiko