Re: [PATCH] drm/dp: annotate implicit fall throughs

[Gustavo A. R. Silva]

On 1/14/19 2:27 PM, Mathieu Malaterre wrote:
> There is a plan to build the kernel with -Wimplicit-fallthrough and
> these places in the code produced warnings (W=1). Fix them up.
>
> This commit remove the following warnings:
>
>    include/linux/compiler.h:77:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    include/asm-generic/bug.h:134:2: note: in expansion of macro 'unlikely'
>    drivers/gpu/drm/drm_dp_helper.c:155:3: note: in expansion of macro 'WARN'
>    include/linux/compiler.h:77:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    include/asm-generic/bug.h:134:2: note: in expansion of macro 'unlikely'
>    drivers/gpu/drm/drm_dp_helper.c:173:3: note: in expansion of macro 'WARN'
>    drivers/gpu/drm/drm_dp_helper.c:547:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
>
> Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx>
Acked-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

> ---
>   drivers/gpu/drm/drm_dp_helper.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 516e82d0ed50..26835d174939 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -154,6 +154,7 @@ u8 drm_dp_link_rate_to_bw_code(int link_rate)
>   	default:
>   		WARN(1, "unknown DP link rate %d, using %x\n", link_rate,
>   		     DP_LINK_BW_1_62);
> +		/* fall through */
>   	case 162000:
>   		return DP_LINK_BW_1_62;
>   	case 270000:
> @@ -171,6 +172,7 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
>   	switch (link_bw) {
>   	default:
>   		WARN(1, "unknown DP link BW code %x, using 162000\n", link_bw);
> +		/* fall through */
>   	case DP_LINK_BW_1_62:
>   		return 162000;
>   	case DP_LINK_BW_2_7:
> @@ -552,6 +554,7 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
>   		case DP_DS_16BPC:
>   			return 16;
>   		}
> +		/* fall through */
>   	default:
>   		return 0;
>   	}