block sizes dont seem to matter, tried from 512 bytes to 64K in the
adaptec case. i also get no errors in /dev/kprint. just read() returns
Eio.

i have no knowledge of IDE or SATA interfaces, so i'm a little bit lost
in the code. :-( the chipset specific IDE code in linux seens to set
mostly some timing related control registers, but doesnt change
the logic how error conditions are handled as far as i can see. maybe
it does by switching some important quirk flags but its not obvious
to me.

i would like to raise the debug level of sdata.c, just set any bit and got
flooded with messages. so it would be great if you could hint me on
some interesting debug cases where to look.

many thanks so far for the quick responses! :-)

cinap