2019-01-14 20:30:50

by Mathieu Malaterre

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

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 <[email protected]>
---
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;
}
--
2.19.2

2019-01-14 21:24:25

by Gustavo A. R. Silva

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

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 <[email protected]>
Acked-by: Gustavo A. R. Silva <[email protected]>

> ---
> 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;
> }
>

2019-01-15 12:38:49

by Daniel Vetter

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

On Mon, Jan 14, 2019 at 03:13:29PM -0600, Gustavo A. R. Silva wrote:
>
>
> 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 <[email protected]>
> Acked-by: Gustavo A. R. Silva <[email protected]>

Thanks for your patch, applied.
-Daniel

>
> > ---
> > 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;
> > }
> >

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch