ata_host_intr — Handle host interrupt for given (port, task)
Port on which interrupt arrived (possibly...)
Taskfile currently active in engine
Handle host interrupt for given queued command. Currently, only DMA interrupts are handled. All other commands are handled via polling with interrupts disabled (nIEN bit).
spin_lock_irqsave(host lock)
One if interrupt was handled, zero if not (shared irq).