Re: [PATCH] mmc: atmel-mci: Mark expected switch fall-throughs

From: Kees Cook <keescook@chromium.org>
To: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: [PATCH] mmc: atmel-mci: Mark expected switch fall-throughs
Date: Mon, 29 Jul 2019 09:35:40 -0700	[thread overview]
Message-ID: <201907290935.2B95CBC@keescook> (raw)
In-Reply-To: <20190729000123.GA23902@embeddedor>

On Sun, Jul 28, 2019 at 07:01:23PM -0500, Gustavo A. R. Silva wrote:
> Mark switch cases where we are expecting to fall through.
> 
> This patch fixes the following warnings:
> 
> drivers/mmc/host/atmel-mci.c: In function 'atmci_get_cap':
> drivers/mmc/host/atmel-mci.c:2415:30: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    host->caps.has_odd_clk_div = 1;
>    ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
> drivers/mmc/host/atmel-mci.c:2416:2: note: here
>   case 0x400:
>   ^~~~
> drivers/mmc/host/atmel-mci.c:2422:28: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    host->caps.has_highspeed = 1;
>    ~~~~~~~~~~~~~~~~~~~~~~~~~^~~
> drivers/mmc/host/atmel-mci.c:2423:2: note: here
>   case 0x200:
>   ^~~~
> drivers/mmc/host/atmel-mci.c:2426:40: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    host->caps.need_notbusy_for_read_ops = 1;
>    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
> drivers/mmc/host/atmel-mci.c:2427:2: note: here
>   case 0x100:
>   ^~~~
> 
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/mmc/host/atmel-mci.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
> index 9ee0bc0ce6d0..c26fbe5f2222 100644
> --- a/drivers/mmc/host/atmel-mci.c
> +++ b/drivers/mmc/host/atmel-mci.c
> @@ -2413,6 +2413,7 @@ static void atmci_get_cap(struct atmel_mci *host)
>  	case 0x600:
>  	case 0x500:
>  		host->caps.has_odd_clk_div = 1;
> +		/* Fall through */
>  	case 0x400:
>  	case 0x300:
>  		host->caps.has_dma_conf_reg = 1;
> @@ -2420,13 +2421,16 @@ static void atmci_get_cap(struct atmel_mci *host)
>  		host->caps.has_cfg_reg = 1;
>  		host->caps.has_cstor_reg = 1;
>  		host->caps.has_highspeed = 1;
> +		/* Fall through */
>  	case 0x200:
>  		host->caps.has_rwproof = 1;
>  		host->caps.need_blksz_mul_4 = 0;
>  		host->caps.need_notbusy_for_read_ops = 1;
> +		/* Fall through */
>  	case 0x100:
>  		host->caps.has_bad_data_ordering = 0;
>  		host->caps.need_reset_after_xfer = 0;
> +		/* Fall through */
>  	case 0x0:
>  		break;
>  	default:
> -- 
> 2.22.0
> 

-- 
Kees Cook