[PATCH] staging: atomisp: Fix fallthrough keyword warning

[PATCH] staging: atomisp: Fix fallthrough keyword warning

[Cengiz Can]

commit df561f6688fe ("treewide: Use fallthrough pseudo-keyword") from
Gustavo A. R. Silva replaced and standardized /* fallthrough */ comments
with 'fallthrough' pseudo-keyword.

However, in one of the switch-case statements, Coverity Static Analyzer
throws a warning that 'fallthrough' is unreachable due to the adjacent
'return false' statement.

Since 'fallthrough' is actually an empty "do {} while(0)" this might be
due to compiler optimizations. But that needs further investigation.

In order to fix the unreachable code warning, make adjacent 'return
false' a part of the previous if statement's else clause.

Reported-by: Coverity Static Analyzer CID 1466511
Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
---
 drivers/staging/media/atomisp/pci/atomisp_compat_css20.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
index 1b2b2c68025b..aaa2d0e0851b 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
@@ -709,8 +709,8 @@ static bool is_pipe_valid_to_current_run_mode(struct atomisp_sub_device *asd,
 		if (pipe_id == IA_CSS_PIPE_ID_CAPTURE ||
 		    pipe_id == IA_CSS_PIPE_ID_PREVIEW)
 			return true;
-
-		return false;
+		else
+			return false;
 		fallthrough;
 	case ATOMISP_RUN_MODE_VIDEO:
 		if (!asd->continuous_mode->val) {
-- 
2.28.0

Re: [PATCH] staging: atomisp: Fix fallthrough keyword warning

[Dan Carpenter]

On Mon, Aug 31, 2020 at 04:30:12PM +0300, Cengiz Can wrote:
> commit df561f6688fe ("treewide: Use fallthrough pseudo-keyword") from
> Gustavo A. R. Silva replaced and standardized /* fallthrough */ comments
> with 'fallthrough' pseudo-keyword.
> 
> However, in one of the switch-case statements, Coverity Static Analyzer
> throws a warning that 'fallthrough' is unreachable due to the adjacent
> 'return false' statement.
> 
> Since 'fallthrough' is actually an empty "do {} while(0)" this might be
> due to compiler optimizations. But that needs further investigation.
> 
> In order to fix the unreachable code warning, make adjacent 'return
> false' a part of the previous if statement's else clause.
> 
> Reported-by: Coverity Static Analyzer CID 1466511
> Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
> ---
>  drivers/staging/media/atomisp/pci/atomisp_compat_css20.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> index 1b2b2c68025b..aaa2d0e0851b 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> @@ -709,8 +709,8 @@ static bool is_pipe_valid_to_current_run_mode(struct atomisp_sub_device *asd,
>  		if (pipe_id == IA_CSS_PIPE_ID_CAPTURE ||
>  		    pipe_id == IA_CSS_PIPE_ID_PREVIEW)
>  			return true;
> -
> -		return false;
> +		else
> +			return false;
>  		fallthrough;

Heh...  Still unreachable, but now it has a checkpatch.pl warning as
well.  Just get rid of the bogus fallthrough annotation.

>  	case ATOMISP_RUN_MODE_VIDEO:
>  		if (!asd->continuous_mode->val) {

regards,
dan carpenter

Re: [PATCH] staging: atomisp: Fix fallthrough keyword warning

[Dan Carpenter]

Really I think this function is pretty buggy.  It shouldn't be falling
through at all...  I reported it a couple days back so it's possible
that someone is working on a fix already.

regards,
dan carpenter

[PATCH v2] staging: atomisp: Remove unnecessary 'fallthrough'

[Cengiz Can]

commit df561f6688fe ("treewide: Use fallthrough pseudo-keyword") from
Gustavo A. R. Silva replaced and standardized /* fallthrough */ comments
with 'fallthrough' pseudo-keyword.

However, in one of the switch-case statements, Coverity Static Analyzer
throws a warning that 'fallthrough' is unreachable due to the adjacent
'return false' statement. (Coverity ID CID 1466511)

In order to fix the unreachable code warning, remove unnecessary
fallthrough keyword.

Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
---
 drivers/staging/media/atomisp/pci/atomisp_compat_css20.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
index 1b2b2c68025b..feb26c221e96 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
@@ -711,7 +711,6 @@ static bool is_pipe_valid_to_current_run_mode(struct atomisp_sub_device *asd,
 			return true;
 
 		return false;
-		fallthrough;
 	case ATOMISP_RUN_MODE_VIDEO:
 		if (!asd->continuous_mode->val) {
 			if (pipe_id == IA_CSS_PIPE_ID_VIDEO ||
-- 
2.28.0

Re: [PATCH v2] staging: atomisp: Remove unnecessary 'fallthrough'

[Gustavo A. R. Silva]

On Mon, Aug 31, 2020 at 04:51:04PM +0300, Cengiz Can wrote:
> commit df561f6688fe ("treewide: Use fallthrough pseudo-keyword") from
> Gustavo A. R. Silva replaced and standardized /* fallthrough */ comments
> with 'fallthrough' pseudo-keyword.
> 
> However, in one of the switch-case statements, Coverity Static Analyzer
> throws a warning that 'fallthrough' is unreachable due to the adjacent
> 'return false' statement. (Coverity ID CID 1466511)
> 
> In order to fix the unreachable code warning, remove unnecessary
> fallthrough keyword.
> 
> Signed-off-by: Cengiz Can <cengiz@kernel.wtf>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
>  drivers/staging/media/atomisp/pci/atomisp_compat_css20.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> index 1b2b2c68025b..feb26c221e96 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> @@ -711,7 +711,6 @@ static bool is_pipe_valid_to_current_run_mode(struct atomisp_sub_device *asd,
>  			return true;
>  
>  		return false;
> -		fallthrough;
>  	case ATOMISP_RUN_MODE_VIDEO:
>  		if (!asd->continuous_mode->val) {
>  			if (pipe_id == IA_CSS_PIPE_ID_VIDEO ||
> -- 
> 2.28.0
> 

Re: [PATCH] staging: atomisp: Fix fallthrough keyword warning

[Mauro Carvalho Chehab]

Em Mon, 31 Aug 2020 16:30:12 +0300
Cengiz Can <cengiz@kernel.wtf> escreveu:

> commit df561f6688fe ("treewide: Use fallthrough pseudo-keyword") from
> Gustavo A. R. Silva replaced and standardized /* fallthrough */ comments
> with 'fallthrough' pseudo-keyword.
> 
> However, in one of the switch-case statements, Coverity Static Analyzer
> throws a warning that 'fallthrough' is unreachable due to the adjacent
> 'return false' statement.
> 
> Since 'fallthrough' is actually an empty "do {} while(0)" this might be
> due to compiler optimizations. But that needs further investigation.
> 
> In order to fix the unreachable code warning, make adjacent 'return
> false' a part of the previous if statement's else clause.
> 
> Reported-by: Coverity Static Analyzer CID 1466511
> Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
> ---
>  drivers/staging/media/atomisp/pci/atomisp_compat_css20.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> index 1b2b2c68025b..aaa2d0e0851b 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> @@ -709,8 +709,8 @@ static bool is_pipe_valid_to_current_run_mode(struct atomisp_sub_device *asd,
>  		if (pipe_id == IA_CSS_PIPE_ID_CAPTURE ||
>  		    pipe_id == IA_CSS_PIPE_ID_PREVIEW)
>  			return true;
> -
> -		return false;
> +		else
> +			return false;
>  		fallthrough;

Actually, the actual fix here would be to get rid of fallthrough.

Regards,

Thanks,
Mauro