[PATCH] ath10k: fix system hang at qca99x0 probe on x86 platform

Adrian Chadd adrian at freebsd.org
Tue Jul 19 22:44:40 PDT 2016


dma coherent doesn't /have/ to mean "low 32 bits". It's just supposed
to mean "try really hard to use uncached memory on platforms that
support it."

The ath10k hardware (at least what I've played with thus far) is all
32 bit DMA hardware, not 64 bit, so it can't be handed 64 bit memory -
contiguous or otherwise.

So, if dma coherent on linux means 32 bit only physmem, great.

Now, it also turns out that various platforms that say they do
coherent memory these days do "mostly coherent", and you still need
some flush/sync ops..


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