>> I don't think the sio multiport stuff needs to use RF_SHAREABLE - the >> master device knows how to field interrupts for the slaves (at least thats >> how I understood it). > >But the sio non-multiport stuff should be able to use RF_TIMESHARE. -- >If I'm not using my serial port, I should be able to use my >infrared....
Preemptive timesharing would be hard to implement reasonably for irqs. A uniform timeslice would have to be 86 usec to work properly for unbuffered sio devices at 115200 bps. This is not reasonable, so the interrupt system would have to guess which device you are using and only switch irqs away from it every few [hundred] msec. This would work better for slower and output-mostly devices, mainly for printers. Bruce To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-current" in the body of the message
