On Saturday 27 October 2012 09:29 PM, Paul Walmsley wrote:

On Sat, 27 Oct 2012, Santosh Shilimkar wrote:

quoted

Another alternative, which I will recommend to just make use of the
read*/wrire* instead __raw versions. The barriers are taken care
already and driver point of view, it is transparent.

Those barriers will disappear if CONFIG_ARM_DMA_MEM_BUFFERABLE is set to
N, so that's probably not the right thing to do in this case.  The barrier
here isn't DMA-related, it's needed due to the design of the driver.

Good point.

In fact the wmb() is probably overkill, since only a compiler reordering
barrier is needed.  It can probably just be barrier().

I agree. Just barrier() is enough to avoid compiler re-ordering.

Regards
Santosh