Re: [PATCH] scsi: mpt3sas: Mark expected switch fall-through

[Kees Cook]

On Tue, Jun 11, 2019 at 10:02:19AM -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 warning:
> 
> drivers/scsi/mpt3sas/mpt3sas_base.c: In function â_base_update_ioc_page1_inlinewith_perf_modeâ:
> drivers/scsi/mpt3sas/mpt3sas_base.c:4510:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    if (ioc->high_iops_queues) {
>       ^
> drivers/scsi/mpt3sas/mpt3sas_base.c:4530:2: note: here
>   case MPT_PERF_MODE_LATENCY:
>   ^~~~
> 
> 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>

Fixes: 30cb97023f38 ("scsi: mpt3sas: Introduce perf_mode module parameter")
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
>  drivers/scsi/mpt3sas/mpt3sas_base.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
> index e6377ec07f6c..9fefcd1e9c97 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_base.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
> @@ -4527,6 +4527,7 @@ _base_update_ioc_page1_inlinewith_perf_mode(struct MPT3SAS_ADAPTER *ioc)
>  			ioc_info(ioc, "performance mode: balanced\n");
>  			return;
>  		}
> +		/* Fall through */
>  	case MPT_PERF_MODE_LATENCY:
>  		/*
>  		 * Enable interrupt coalescing on all reply queues
> -- 
> 2.21.0
> 

-- 
Kees Cook