UART misbehaves under Linkstation/KuroBoxHG

[Oncaphillis <oncaphillis@snafu.de>]

Greetings,

I'm trying to compile a 2.6.2x kernel on a Linkstation/KuroBox HG/ppc
following instructions given under 
http://www.kurobox.com/mwiki/index.php/Kurobox_support_in_stock_2.6_kernels 
and get weired settings and errors from the serial device (UART 16550A).

Under the 2.4.17 kernel provided by the Kurobox manufacturer it gets 
IRQS in the range of 137/138 under 2.6.22 for the linkstation it gets 
IRQS 17/18 and the serial device behaves fishy

communication errors

"to much work in IRQ 16"

stty -F /dev/ttyS0 sometimes tells me
"unable to perform all requested operations"

setserial tells me the port for /dev/ttyS0 is 0x000 (?)
while cat /proc/tty/driver/serial reports the proper mmio
0x80004500

This holds true for 2.6.20 and 2.6.22.1

Any suggestions ?

Thanks for listening.