scatterlist.c or dma_map_sg() should coalesce?

From: Leon Woestenberg
Date: Sun Sep 28 2008 - 11:54:14 EST


Hello,

in 2.6.27+, if I want to create a scatterlist of a large buffer in
virtual memory in a device driver, can I expect the scatterlist and/or
mapping API to provide me with a minimal list, each entry describing a
maximum bus-contiguous piece of memory? (i.e. can I assume coalescing
is done for me?).

In 2.6.24, dma_map_sg() *may* coalesce, but doesn't do so for my
platform, so for optimal DMA transfers the device driver needs to
coalesce the list entries.

Regards,
--
Leon
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