> I know that at least the i810 driver in XF 4 wants to allocate 
> and bind 8M. That's unfortunately too much to reserve at attach time.

Ah, I see.

And now I understand the same problem may occur in a driver for the
card dynamically attached.  Perhaps IEEE 1394 cardbus driver may
requires some amount of memory to capture Digital Video, but not
enough memory may be available at the card insertion time.

Though I'm not sure it is possible to implement the policy,
I agree that there must be an interface to wait for getting more
memory suitable for DMA.

Atsushi Onoe