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

From: David S. Miller <davem_at_redhat.com>
Date: 2003-05-16 10:03:58
   From: Colin Ngam <cngam@sgi.com>
   Date: Thu, 15 May 2003 18:40:22 -0500
   
   What I did say is that, on our platform, in PCI-X mode, our PCI-X
   Bridge Chipset do NOT support 32-Bit DMA Bus Space.

Sounds like you can't use a whole swath of devices then.
What an entirely unfortunate design decision.

Anyways, now that I understand the problem, merely adding
the consistent_dma_mask attribute to the device struct will
allow drivers to indicate this capability just fine.
The driver goes:

	if (pci_set_consistent_dma_mask(pdev, ~(u64)0))
		goto probe_error;

and then the platform pci_alloc_consistent() can do whatever is
appropriate.
Received on Thu May 15 17:06:56 2003

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