Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 5 Apr 2019 05:50:32 -1000 | Subject | Re: [PATCH v2 17/21] drivers: Remove explicit invocations of mmiowb() |
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On Fri, Apr 5, 2019 at 4:01 AM Will Deacon <will.deacon@arm.com> wrote: > > mmiowb() is now implied by spin_unlock() on architectures that require > it, so there is no reason to call it from driver code. This patch was > generated using coccinelle: > > @mmiowb@ > @@ > - mmiowb();
So I love the patch series, and think we should just do it, but I do wonder if some of the drivers involved end up relying on memory ordering things (store_release -> load_aquire) and IO ordering rather than using locking...
Wouldn't such use now be broken on ia64 SN platforms? Do we care?
So it might be worth noting that a lot of the mmiowb()s here weren't paired with spin_unlock?
Linus
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