2019-07-26 11:30:42

by Anders Roxell

[permalink] [raw]
Subject: [PATCH] drm: mali-dp: Mark expected switch fall-through

When fall-through warnings was enabled by default, commit d93512ef0f0e
("Makefile: Globally enable fall-through warning"), the following
warnings was starting to show up:

../drivers/gpu/drm/arm/malidp_hw.c: In function ‘malidp_format_get_bpp’:
../drivers/gpu/drm/arm/malidp_hw.c:387:8: warning: this statement may fall
through [-Wimplicit-fallthrough=]
bpp = 30;
~~~~^~~~
../drivers/gpu/drm/arm/malidp_hw.c:388:3: note: here
case DRM_FORMAT_YUV420_10BIT:
^~~~
../drivers/gpu/drm/arm/malidp_hw.c: In function ‘malidp_se_irq’:
../drivers/gpu/drm/arm/malidp_hw.c:1311:4: warning: this statement may fall
through [-Wimplicit-fallthrough=]
drm_writeback_signal_completion(&malidp->mw_connector, 0);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/arm/malidp_hw.c:1313:3: note: here
case MW_START:
^~~~

Rework to add a 'break;' in a case that didn't have it so that
the compiler doesn't warn about fall-through.

Cc: [email protected] # v4.9+
Fixes: b8207562abdd ("drm/arm/malidp: Specified the rotation memory requirements for AFBC YUV formats")
Signed-off-by: Anders Roxell <[email protected]>
---
drivers/gpu/drm/arm/malidp_hw.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
index 50af399d7f6f..dc5fff9af338 100644
--- a/drivers/gpu/drm/arm/malidp_hw.c
+++ b/drivers/gpu/drm/arm/malidp_hw.c
@@ -385,6 +385,7 @@ int malidp_format_get_bpp(u32 fmt)
switch (fmt) {
case DRM_FORMAT_VUY101010:
bpp = 30;
+ break;
case DRM_FORMAT_YUV420_10BIT:
bpp = 15;
break;
@@ -1309,7 +1310,7 @@ static irqreturn_t malidp_se_irq(int irq, void *arg)
break;
case MW_RESTART:
drm_writeback_signal_completion(&malidp->mw_connector, 0);
- /* fall through to a new start */
+ /* fall through */
case MW_START:
/* writeback started, need to emulate one-shot mode */
hw->disable_memwrite(hwdev);
--
2.20.1



2019-07-29 09:59:10

by Liviu Dudau

[permalink] [raw]
Subject: Re: [PATCH] drm: mali-dp: Mark expected switch fall-through

Hi Anders,

On Fri, Jul 26, 2019 at 01:27:41PM +0200, Anders Roxell wrote:
> When fall-through warnings was enabled by default, commit d93512ef0f0e
> ("Makefile: Globally enable fall-through warning"), the following
> warnings was starting to show up:
>
> ../drivers/gpu/drm/arm/malidp_hw.c: In function ‘malidp_format_get_bpp’:
> ../drivers/gpu/drm/arm/malidp_hw.c:387:8: warning: this statement may fall
> through [-Wimplicit-fallthrough=]
> bpp = 30;
> ~~~~^~~~
> ../drivers/gpu/drm/arm/malidp_hw.c:388:3: note: here
> case DRM_FORMAT_YUV420_10BIT:
> ^~~~
> ../drivers/gpu/drm/arm/malidp_hw.c: In function ‘malidp_se_irq’:
> ../drivers/gpu/drm/arm/malidp_hw.c:1311:4: warning: this statement may fall
> through [-Wimplicit-fallthrough=]
> drm_writeback_signal_completion(&malidp->mw_connector, 0);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/gpu/drm/arm/malidp_hw.c:1313:3: note: here
> case MW_START:
> ^~~~
>
> Rework to add a 'break;' in a case that didn't have it so that
> the compiler doesn't warn about fall-through.
>
> Cc: [email protected] # v4.9+
> Fixes: b8207562abdd ("drm/arm/malidp: Specified the rotation memory requirements for AFBC YUV formats")
> Signed-off-by: Anders Roxell <[email protected]>

Running the patch through scripts/get_maintainer.pl would've also given you the
emails for the mali-dp maintainers to reach directly and have a faster response
time, but I guess you were trying to see if we check the dri-devel mailing list.

Thanks for the patch!

Acked-by: Liviu Dudau <[email protected]>

Best regards,
Liviu

> ---
> drivers/gpu/drm/arm/malidp_hw.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
> index 50af399d7f6f..dc5fff9af338 100644
> --- a/drivers/gpu/drm/arm/malidp_hw.c
> +++ b/drivers/gpu/drm/arm/malidp_hw.c
> @@ -385,6 +385,7 @@ int malidp_format_get_bpp(u32 fmt)
> switch (fmt) {
> case DRM_FORMAT_VUY101010:
> bpp = 30;
> + break;
> case DRM_FORMAT_YUV420_10BIT:
> bpp = 15;
> break;
> @@ -1309,7 +1310,7 @@ static irqreturn_t malidp_se_irq(int irq, void *arg)
> break;
> case MW_RESTART:
> drm_writeback_signal_completion(&malidp->mw_connector, 0);
> - /* fall through to a new start */

It's a shame that the compiler throws a warning here, it would've been really
useful to keep the hint that going back to a new start is intentional without
having to type another comment.

> + /* fall through */
> case MW_START:
> /* writeback started, need to emulate one-shot mode */
> hw->disable_memwrite(hwdev);
> --
> 2.20.1
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯

2019-07-29 13:18:47

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH] drm: mali-dp: Mark expected switch fall-through



On 7/29/19 4:58 AM, Liviu Dudau wrote:

>> case MW_RESTART:
>> drm_writeback_signal_completion(&malidp->mw_connector, 0);
>> - /* fall through to a new start */
>
> It's a shame that the compiler throws a warning here, it would've been really
> useful to keep the hint that going back to a new start is intentional without
> having to type another comment.
>

You don't have to remove the rest of the comment. For a one-line comment this works
just fine:

/* fall through - to a new start */

--
Gustavo