From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Anders Roxell <anders.roxell@linaro.org>, arnd@arndb.de
Cc:     nathan@kernel.org, ndesaulniers@google.com,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, Anders Roxell <anders.roxell@linaro.org>,
        Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: Re: [PATCH] powerpc: platforms: cell: pervasive: fix clang
 -Wimplicit-fallthrough
In-Reply-To: <20211207110228.698956-1-anders.roxell@linaro.org>
References: <20211207110228.698956-1-anders.roxell@linaro.org>
Date:   Thu, 09 Dec 2021 17:40:24 +1100
Message-ID: <87zgpamgbr.fsf@mpe.ellerman.id.au>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Anders Roxell <anders.roxell@linaro.org> writes:
> Clang warns:
>
> arch/powerpc/platforms/cell/pervasive.c:81:2: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]
>         case SRR1_WAKEEE:
>         ^
> arch/powerpc/platforms/cell/pervasive.c:81:2: note: insert 'break;' to avoid fall-through
>         case SRR1_WAKEEE:
>         ^
>         break;
> 1 error generated.
>
> Clang is more pedantic than GCC, which does not warn when failing
> through to a case that is just break or return. Clang's version
> is more in line with the kernel's own stance in deprecated.rst.
> Add athe missing break to silence the warning.
>
> Fixes: 6e83985b0f6e ("powerpc/cbe: Do not process external or decremeter interrupts from sreset")
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
> ---
>  arch/powerpc/platforms/cell/pervasive.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/powerpc/platforms/cell/pervasive.c b/arch/powerpc/platforms/cell/pervasive.c
> index 5b9a7e9f144b..dff8d5e7ab82 100644
> --- a/arch/powerpc/platforms/cell/pervasive.c
> +++ b/arch/powerpc/platforms/cell/pervasive.c
> @@ -78,6 +78,7 @@ static int cbe_system_reset_exception(struct pt_regs *regs)
>  	switch (regs->msr & SRR1_WAKEMASK) {
>  	case SRR1_WAKEDEC:
>  		set_dec(1);
> +		break;
>  	case SRR1_WAKEEE:
>  		/*
>  		 * Handle these when interrupts get re-enabled and we take

Thanks. I have definitely fixed this somewhere before, but I guess I
never sent it upstream, or it's still lying in a git stash of mine.

cheers