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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Wed, 6 May 2020 09:37:16 -0700
Message-ID: <CAKwvOd=c6gzpUsRgh-XmKEh0xHkZUWfXNW52EpqfrbH+XhH5fQ@mail.gmail.com>
Subject: Re: [PATCH] x86: bitops: fix build regression
To:     Nathan Chancellor <natechancellor@gmail.com>,
        Ilie Halip <ilie.halip@gmail.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Sedat Dilek <sedat.dilek@gmail.com>,
        "# 3.4.x" <stable@vger.kernel.org>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        "kernelci . org bot" <bot@kernelci.org>,
        Andy Shevchenko <andriy.shevchenko@intel.com>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Marco Elver <elver@google.com>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Daniel Axtens <dja@axtens.net>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>
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On Tue, May 5, 2020 at 9:30 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Tue, May 05, 2020 at 10:44:22AM -0700, Nick Desaulniers wrote:
> > This is easily reproducible via Clang+CONFIG_STAGING=y+CONFIG_VT6656=m,
> > or Clang+allyesconfig.
>
> For what it's worth, I don't see this with allyesconfig.

Oops, ok, I'll drop that from the commit message in v2.  I was testing
with the former.

>
> > Keep the masking operation to appease sparse (`make C=1`), add back the
> > cast in order to properly select the proper 8b register alias.
> >
> >  [Nick: reworded]
> >
> > Cc: stable@vger.kernel.org
>
> The offending commit was added in 5.7-rc1; we shouldn't need to
> Cc stable since this should be picked up as an -rc fix.

Got it, will drop in v2.

>
> > Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
> > Link: https://github.com/ClangBuiltLinux/linux/issues/961
> > Link: https://lore.kernel.org/lkml/20200504193524.GA221287@google.com/
> > Fixes: 1651e700664b4 ("x86: Fix bitops.h warning with a moved cast")
> > Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> > Reported-by: kernelci.org bot <bot@kernelci.org>
> > Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
> > Suggested-by: Ilie Halip <ilie.halip@gmail.com>
>
> Not to split hairs but this is Ilie's diff, he should probably be the
> author with Sedat's Reported-by/Tested-by.
>
> https://github.com/ClangBuiltLinux/linux/issues/961#issuecomment-608239458

Ooh, you're right. Sorry about that Ilie.  I'm usually pretty pedantic
about getting that right; my mistake.  I'll fix that in v2.  As Sedat
noted, the issue tracker has been a little quiet on this issue, but
I'll note that there are extraordinary circumstances going on in the
world these days (COVID) so delays should be anticipated.

Ilie, may I put your authorship and signed off by tag on the V2?

>
> But eh, it's all a team effort plus that can only happen with Ilie's
> explicit consent for a Signed-off-by.
-- 
Thanks,
~Nick Desaulniers