On Sun, 16 Mar 2008, Alan Cox wrote:
quoted text
> 
> No it doesn't. DRQ simply means "drive has more data for the controller
> if you want it". Interrupts are controlled via IEN and the interrupt line.

A _lot_ of chips require you to clear the DRQ by taking the data they 
have.

quoted text
> If the drive wants to give us data and we end the transaction that is
> fine. In practice a tiny few devices crap themselves if we don't.

More than a few tiny devices from what I remember. It tends to be the 
other way around - most devices do *not* want to get new commands until 
you've finished the previous one by draining the queues.

		Linus
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