Writing Device Drivers

Untagged Queueing

If tagged queueing fails, you can attempt to set untagged queuing. In this mode, you submit as many commands as you think necessary or optimal to the host adapter driver. Then, the host adapter queues the commands to the target one at a time (as opposed to tagged queueing, where the host adapter submits as many commands as it can until the target indicates that the queue is full).