[PATCH] media: imx: shut up a false positive warning

[PATCH] media: imx: shut up a false positive warning

[Mauro Carvalho Chehab]

With imx, gcc produces a false positive warning:

	drivers/staging/media/imx/imx-media-csi.c: In function 'csi_idmac_setup_channel':
	drivers/staging/media/imx/imx-media-csi.c:457:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
	   if (passthrough) {
	      ^
	drivers/staging/media/imx/imx-media-csi.c:464:2: note: here
	  default:
	  ^~~~~~~

That's because the regex it uses for fall trough is not
good enough. So, rearrange the fall through comment in a way
that gcc will recognize.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/staging/media/imx/imx-media-csi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index 4647206f92ca..b7ffd231c64b 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -460,7 +460,8 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
 			passthrough_cycles = incc->cycles;
 			break;
 		}
-		/* fallthrough for non-passthrough RGB565 (CSI-2 bus) */
+		/* for non-passthrough RGB565 (CSI-2 bus) */
+		/* Falls through */
 	default:
 		burst_size = (image.pix.width & 0xf) ? 8 : 16;
 		passthrough_bits = 16;
-- 
2.17.1

Re: [PATCH] media: imx: shut up a false positive warning

[Ian Arkver]

Hi Mauro,

On 07/08/18 10:58, Mauro Carvalho Chehab wrote:
> With imx, gcc produces a false positive warning:
> 
> 	drivers/staging/media/imx/imx-media-csi.c: In function 'csi_idmac_setup_channel':
> 	drivers/staging/media/imx/imx-media-csi.c:457:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> 	   if (passthrough) {
> 	      ^
> 	drivers/staging/media/imx/imx-media-csi.c:464:2: note: here
> 	  default:
> 	  ^~~~~~~
> 
> That's because the regex it uses for fall trough is not
> good enough. So, rearrange the fall through comment in a way
> that gcc will recognize.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
> ---
>   drivers/staging/media/imx/imx-media-csi.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
> index 4647206f92ca..b7ffd231c64b 100644
> --- a/drivers/staging/media/imx/imx-media-csi.c
> +++ b/drivers/staging/media/imx/imx-media-csi.c
> @@ -460,7 +460,8 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
>   			passthrough_cycles = incc->cycles;
>   			break;
>   		}
> -		/* fallthrough for non-passthrough RGB565 (CSI-2 bus) */
> +		/* for non-passthrough RGB565 (CSI-2 bus) */
> +		/* Falls through */

Adding a '-' to the fallthrough seems to meet the regex requirements at 
level 3 of the warning. Eg...

/* fallthrough- for non-passthrough RGB565 (CSI-2 bus) */

Not sure if this is an improvement though.

Regards,
Ian

>   	default:
>   		burst_size = (image.pix.width & 0xf) ? 8 : 16;
>   		passthrough_bits = 16;
> 

Re: [PATCH] media: imx: shut up a false positive warning

[Mauro Carvalho Chehab]

Em Tue, 7 Aug 2018 12:00:46 +0100
Ian Arkver <ian.arkver.dev@gmail.com> escreveu:

> Hi Mauro,
> 
> On 07/08/18 10:58, Mauro Carvalho Chehab wrote:
> > With imx, gcc produces a false positive warning:
> > 
> > 	drivers/staging/media/imx/imx-media-csi.c: In function 'csi_idmac_setup_channel':
> > 	drivers/staging/media/imx/imx-media-csi.c:457:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> > 	   if (passthrough) {
> > 	      ^
> > 	drivers/staging/media/imx/imx-media-csi.c:464:2: note: here
> > 	  default:
> > 	  ^~~~~~~
> > 
> > That's because the regex it uses for fall trough is not
> > good enough. So, rearrange the fall through comment in a way
> > that gcc will recognize.
> > 
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
> > ---
> >   drivers/staging/media/imx/imx-media-csi.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
> > index 4647206f92ca..b7ffd231c64b 100644
> > --- a/drivers/staging/media/imx/imx-media-csi.c
> > +++ b/drivers/staging/media/imx/imx-media-csi.c
> > @@ -460,7 +460,8 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
> >   			passthrough_cycles = incc->cycles;
> >   			break;
> >   		}
> > -		/* fallthrough for non-passthrough RGB565 (CSI-2 bus) */
> > +		/* for non-passthrough RGB565 (CSI-2 bus) */
> > +		/* Falls through */  
> 
> Adding a '-' to the fallthrough seems to meet the regex requirements at 
> level 3 of the warning. Eg...
> 
> /* fallthrough- for non-passthrough RGB565 (CSI-2 bus) */
> 
> Not sure if this is an improvement though.

Hmm... this also works:

/* fallthrough - non-passthrough RGB565 (CSI-2 bus) */

I would actually prefer a ':' instead of '-', but that works too,
and it could be better than splitting fall through messages on
two comments.

Thanks,
Mauro