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

[Mauro Carvalho Chehab <mchehab+samsung@kernel.org>]

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