From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] skge: add dma_mapping check
Date: Sat, 10 Aug 2013 13:29:35 -0700 (PDT)
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From: Stephen Hemminger <stephen@networkplumber.org>
Date: Sat, 10 Aug 2013 10:41:00 -0700

> The DMA debug check insists that the call to sync_single has
> to be the same length as the mapping. The driver is only bothering
> to sync the bytes that matter (got received) rather than the whole
> map.
> 
> In reality that is not required, but I will make a patch anyway.

PCI and other system controllers will prefetch, I think it can matter.