BAR set to 0 - all the bits have to be 0, right?

[mek@sco.com]

We're tripping across an Intel host bridge that is setting _just_ the
prefetchable bit in its BAR to 0. All other bits in that BAR (and all the other
BARs) are 0.

Is this legal? What does it mean to say 'the memory range is prefetchable' when
you _don't_ specify a memory range? This is on a laptop, I can dig out the
device ID, vendor ID is Intel.

If one is trying to compute memory range used, should you just check bits
4-32 (or -64) for 0 before ignoring the BAR? Or check all 32 bits...?

Matt