Re: [PATCH] watchdog: machzwd: Mark expected switch fall-through

[Guenter Roeck]

On Wed, Apr 10, 2019 at 01:49:05PM -0500, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch
> cases where we are expecting to fall through.
> 
> This patch fixes the following warnings:
> 
> drivers/watchdog/machzwd.c: In function âzf_set_timerâ:
> ./arch/x86/include/asm/io.h:355:14: warning: this statement may fall through [-Wimplicit-fallthrough=]
>  #define outw outw
> drivers/watchdog/machzwd.c:80:53: note: in expansion of macro âoutwâ
>  #define zf_writew(port, data)  { outb(port, INDEX); outw(data, DATA_W); }
>                                                      ^~~~
> drivers/watchdog/machzwd.c:179:3: note: in expansion of macro âzf_writewâ
>    zf_writew(COUNTER_1, new);
>    ^~~~~~~~~
> drivers/watchdog/machzwd.c:180:2: note: here
>   case WD2:
>   ^~~~
> 
> Warning level 3 was used: -Wimplicit-fallthrough=3
> 
> This patch is part of the ongoing efforts to enable
> -Wimplicit-fallthrough.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>  drivers/watchdog/machzwd.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/watchdog/machzwd.c b/drivers/watchdog/machzwd.c
> index 88d823d87a4b..108928dbc754 100644
> --- a/drivers/watchdog/machzwd.c
> +++ b/drivers/watchdog/machzwd.c
> @@ -177,6 +177,7 @@ static inline void zf_set_timer(unsigned short new, unsigned char n)
>  	switch (n) {
>  	case WD1:
>  		zf_writew(COUNTER_1, new);
> +		/* fall through */
>  	case WD2:
>  		zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
>  	default:
> -- 
> 2.21.0
>