lkml.org 
[lkml]   [2019]   [Apr]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 17/21] drivers: Remove explicit invocations of mmiowb()
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

\
 
 \ /
  Last update: 2019-04-05 17:56    [W:0.106 / U:1.276 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site