[Linux-ia64] Re: 64 Bits DMA Addresses for Alloc Consistent Interfaces.

David S. Miller
2003-05-16T00:59:23Z

From: Colin Ngam <cngam@sgi.com>
Date: Thu, 15 May 2003 19:36:55 -0500

I do not believe it is within spec to perform DAC when the
Upper 32bits are 0s.

That is an illogical requirement in that it means PCI-X mode is
illegal in the presence of such addresses. It means that PCI-X
devices cannot work in x86 systems with <4GB of memory which is
obviously not true.