Hi,
Double sorry now.
I don't know if you have been following "RFC on writel and writel_relaxed" thread
or not but there are some new developments about wmb() requirement.
Just out of interest: Where can this thread be found?
Basically, wmb() should never be used before writel() as writel() seem to
provide coherency and observability guarantee.
AFAIU memory-barriers.txt writel() only guarantees correct order of accesses to
IO-memory not RAM vs. IO-memory (this may be the case for some architectures
where the writel() implementation contains a wmb() but not for all).
For the RAM vs. IO-memory case at least a a wmb()/rmb() has to be used.
Is this not correct?
Regards,
Lino