Re: [Linux-ia64] Re: [patch] support 64 bit pci_alloc_consistent

Grant Grundler
2003-05-18T17:22:03Z

On Sun, May 18, 2003 at 09:43:41AM +0000, Arjan van de Ven wrote:
> Most drivers will just say "look I
> can do THIS much. I don't give a flying fish about how much of
> that you actually use". At least in the probing code.

The platform code needs a way to indicate the given mask will not work.
Rejecting proposals by the driver seems reasonable if the driver
only supports two different masks anyway (eg 64 and 32-bit).

In the case of a platform requiring 64-bit masks for consistent mappings,
the platform DMA code must reject proposals for non-64-bit DMA masks.
(eg PCI-X device implementing less than 64-bits)

In both cases the driver will care because it will crash the box otherwise.

grant