linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Michael Ellerman <mpe@ellerman.id.au>
To: Stephen Rothwell <sfr@canb.auug.org.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: PowerPC <linuxppc-dev@lists.ozlabs.org>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	Kees Cook <keescook@chromium.org>,
	Linux kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drivers/macintosh/smu.c: Mark expected switch fall-through
Date: Wed, 31 Jul 2019 00:28:55 +1000	[thread overview]
Message-ID: <878ssfzjdk.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20190730143704.060a2606@canb.auug.org.au>

Stephen Rothwell <sfr@canb.auug.org.au> writes:
> Mark switch cases where we are expecting to fall through.
>
> This patch fixes the following warning (Building: powerpc):
>
> drivers/macintosh/smu.c: In function 'smu_queue_i2c':
> drivers/macintosh/smu.c:854:21: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    cmd->info.devaddr &= 0xfe;
>    ~~~~~~~~~~~~~~~~~~^~~~~~~
> drivers/macintosh/smu.c:855:2: note: here
>   case SMU_I2C_TRANSFER_STDSUB:
>   ^~~~
>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
> Cc: Kees Cook <keescook@chromium.org>
> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> ---
>  drivers/macintosh/smu.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
> index 276065c888bc..23f1f41c8602 100644
> --- a/drivers/macintosh/smu.c
> +++ b/drivers/macintosh/smu.c
> @@ -852,6 +852,7 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
>  		break;
>  	case SMU_I2C_TRANSFER_COMBINED:
>  		cmd->info.devaddr &= 0xfe;
> +		/* fall through */
>  	case SMU_I2C_TRANSFER_STDSUB:
>  		if (cmd->info.sublen > 3)
>  			return -EINVAL;

Why do we think it's an expected fall through? I can't really convince
myself from the surrounding code that it's definitely intentional.

cheers

  parent reply	other threads:[~2019-07-30 14:29 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-30  4:37 [PATCH] drivers/macintosh/smu.c: Mark expected switch fall-through Stephen Rothwell
2019-07-30  4:45 ` Stephen Rothwell
2019-07-30 14:28 ` Michael Ellerman [this message]
2019-07-30 14:41   ` Stephen Rothwell
2019-07-30 17:07   ` Kees Cook
2019-07-30 20:37     ` Benjamin Herrenschmidt
2019-07-31 11:46     ` Michael Ellerman
2019-08-02  2:28 ` Michael Ellerman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=878ssfzjdk.fsf@concordia.ellerman.id.au \
    --to=mpe@ellerman.id.au \
    --cc=benh@kernel.crashing.org \
    --cc=gustavo@embeddedor.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=sfr@canb.auug.org.au \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).