Subject: Re: RFC on writel and writel_relaxed

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 29 Mar 2018 02:13:16 +1100

On Wed, 2018-03-28 at 07:41 -0400, [email-masked] wrote:
> Yes, we want to get there indeed. It is because of some arch not 
> implementing writel properly. Maintainers want to play safe.
> 
> That is why I asked if IA64 and other well known archs follow the 
> strongly ordered rule at this moment like PPC and ARM.
> 
> Or should we go and inform every arch about this before yanking wmb()?
> 
> Maintainers are afraid of introducing a regression.

Let's fix all archs, it's way easier than fixing all drivers. Half of
the archs are unused or dead anyway.

> > 
> > The above code makes no sense, and just looks stupid to me. It also
> > generates pointlessly bad code on x86, so it's bad there too.
> > 
> >                 Linus