On Fri, Apr 6, 2018 at 2:50 PM, <okaya@xxxxxxxxxxxxxx> wrote: > On 2018-04-06 06:19, Arnd Bergmann wrote: >> >> On Thu, Apr 5, 2018 at 3:09 PM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote: >>> >> >> I would guess that at least s390 doesn't need the barriers >> (maintainers on Cc now), but there may be others that want to >> override the new barriers with weaker ones where an MMIO >> access is guaranteed to serialize against DMA, or where >> a specialized barrier for this case exists. >> >> Looking over the asm-generic implementation once more now, >> I wonder if we should change the relaxed accessors to not have >> any barriers (back to the version before your series) rather than >> defaulting them to having the same barriers as the regular >> readl/writel. > > > I can do a follow up patch. You want to map them to raw api without any > barriers as before. Right? Right, but of course with the byteswap. Arnd