Sleep and Wake up

[Abu Rasheda]

I am testing my driver on much faster host processor and facing
following issues:

My host is too powerful and it can fill up device buffer queue very fast.

I get best performance when I do busy wait, but this is not desirable
and is bad design.

I need to sleep and wake up quickly and predictability. Indication
from device that queue has space, is coming in form of memory write
(device writes to a memory location of i86 processor).

I tried using wait_event_interruptible_timeout, I am depending on 2nd
parameter of the function but it wake up is too slow, even tried using
value of 1.

Any suggestions ?