intrdisable() will always be able to unregister the interrupt
now, so there is no reason to have it return an error value.
all drivers except uart8250 already assumed it to never fail
and theres no need to maintain that complexity.
access to non standard serial port COM3 at i/o port 0x200 causes
kernel panic on some machines (Toshiba Sattelite 1415-S115). also,
some machines have gameport at 0x200.
i readded uartisa to the pcf and pccpuf kernel configurations so
one can use plan9.ini to add non standard uarts like:
uart2=type=isa port=0x200 irq=5
cinap_lenrek
cinap_lenrek
cinap_lenrek
stanley lieber
Taru Karttunen