Re: [PATCH 3/3] reset: socfpga: use readl/writel_relaxed

From: Arnd Bergmann
Date: Tue Jul 05 2016 - 07:18:15 EST


On Tuesday, July 5, 2016 12:17:52 PM CEST Philipp Zabel wrote:
> This just removes the rmb()/wmb() pair between register read and
> write. Since no relevant reads follow the rmb and no relevant writes
> precede the wmb, they should be safe to remove.
>
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>

We should only do this if you are fixing a bug (which you don't mention
in the changelog), or if you can show a relevant performance
improvement. Is this code ever used in a fast path? If it is,
wouldn't that indicate a problem in some driver?

Arnd