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
