> > David and others have observed that under heavy load a ZIP drive can
> > cause systems to freeze. The ppa adapter doesn't generate an
interrupt,
>
> Can you not get the thing to give you an interrupt does it not waggle
paper > out or ack or anything useful ?
It waggles ack when the attached device (the disk) is selected which
is not very useful since this is the only pin that will generate
hardware interrupts.
> > so the driver must simulate interrupts using task queues. There are
two > > basic choices: tq_scheduler and tq_timer.
>
> Or add_timer() a timer of your own.
Hmm...
Can add_timer() do 1000 us call backs??
>> I've since switched to using tq_timer with more stable results but
>> apparently there has been a performance drop. Any suggestions?
>
>Add it to both queues and take it off the other when it is called ?
Fine except for one minor problem, I can't find a routine to remove a
request once it is on a task queue. Either that or I'm looking at a
very old <linux/tqueue.h>.
David Campbell