On 13 Nov 2005, at 18:28, Harry Butterworth wrote:
Is this the right approach? Is the check in dma_map_single overzealous?
When running on Xen, just because Linux has allocated adjacent pages
from its 'physical' memory map, doesn't mean they really are physically
contiguous. For I/O we have to go to extra effort to really allocate
truly contiguous multi-page extents.
So your code is correct. If you can preallocate buffers then you could
do that with dma_alloc_coherent and that would guarantee contigous
buffers....
-- Keir
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