Re: PATCH 2.5.x disable BAR when sizing

[David Mosberger]

>>>>> On Fri, 20 Dec 2002 05:57:23 +0000 (UTC), [e-mail] (Linus Torvalds) said:

  Linus> DO NOT DO THIS. It locks up some machines at
  Linus> bootup. Hard. Total bus lockup if you have legacy USB enabled
  Linus> (or anything else that does DMA, for that matter) at the same
  Linus> time as probing the northbridge with this.

  Linus> Trust me.  If you have some new silly ia64-specific bug, the
  Linus> fix is _not_ to break real and existing hardware out there.

Could you please stop this ia64 paranoia and instead explain to me why
it's OK to relocate a PCI device to (0x100000000-PCI_dev_size)
temporarily?  That just seems horribly unsafe to me.  The PCI spec
seems to say the same as it says pretty clearly that memory decoding
should be disabled during BAR-sizing.  If certain bridges cause
problems, perhaps those need to be special-cased?

	--david