Re: alpha iommu fixes

[Andrew Morton]

Andrea Arcangeli wrote:
> 
> On Sun, May 20, 2001 at 03:49:58PM +0200, Andrea Arcangeli wrote:
> > they returned zero. You either have to drop the skb or to try again later
> > if they returns zero.
> 
> BTW, pci_map_single is not a nice interface, it cannot return bus
> address 0, so once we start the fixage it is probably better to change
> the interface as well to get either the error or the bus address via a
> pointer passed to the function.
> 

Would it not be sufficient to define a machine-specific
macro which queries it for error?  On x86 it would be:

#define BUS_ADDR_IS_ERR(addr)	((addr) == 0)

I can't find *any* pci_map_single() in the 2.4.4-ac9 tree
which can fail, BTW.

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