dom0 is stalled until a keypress

[Rafal Wojtczuk <rafal@invisiblethingslab.com>]

Hello,
The following bizarre behaviour was observed on xen4.1+suse dom0 2.6.38, on
an old Core Duo laptop; maybe someone can hint what is wrong.
Dom0 boot stalls after an init.d script prints "Starting udev". Then nothing 
seems to happen. I need to press any key to observe progress - I need to do 
it tens of times for the boot to finish. After X starts fine, then there is 
no need for keypressing anymore.
A particularly disturbing fact is that qrexec_daemon parent, that basically
does
for (;;) { sleep(1); fprintf(stderr, "."); }
does not print dots, until a keypress arrives. So something is very wrong
with timers.
Somehow similarly, pm-suspend sometimes hangs at some stage - after detaching
power cord, machine enters S3 immediately.
This is vaguely similar to the issue described in
 https://lkml.org/lkml/2008/9/14/122
but this time, "nohz=off" does not help.

"cpufreq=dom0-kernel" cures the symptoms; but it is not a sideeffectless 
solution. Any idea what is going on or how to debug it ?

Regards,
RW