Hi Andy,

On Thu, Jun 12, 2014 at 06:51:18PM +0300, Andy Shevchenko wrote:

The documentation says that we have to sync DMA regions after CPU access and
before any DMA transfer is going on. The actual DMA for buffer happens when we
call dmaengine_submit() (*). The original code syncs data after this call which
might lead to the corrupted data in actual stream.

(*) Accordingly to the Documentation/dmaengine.txt the dmaengine_submit call
shouldn't do the transfer, but some DMA controller drivers abuse this rule.
Thus, we would like to have this patch until all DMA controller drivers will be
fixed. Even after that it will be harmless.

It's probable better that we directly fix the DMA engine drivers
instead of working around the issue here.


Thanks,

-- 
heikki