Re: [BUG] x86_64 pci_map_sg modifies sg list - fails multiple map/unmaps

David S. Miller
2004-01-05T19:33:53Z

On Mon, 5 Jan 2004 13:29:54 -0600 (CST)
Berkley Shands <berkley@cs.wustl.edu> wrote:

> The pci layer is modifying the sg list, and then placing a zero
> in the length field. pci-gart.c at line 453 (2.6.0 sources) checks this length field
> after a retry, sees that it is zero, and bughalts.

Oh that's a bug. It is allowed to modify the dma_length field but not
the physical length field.

I imagine x86_64 is doing this so that there need not be a seperate dma_length
field in the scatter_gather struct defined for that platform, and that's too bad it will
definitely need such a seperate field if it wants to implement coalescing.