Sleep and Wake up

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 ?