Re: Checkpatch query

[Joe Perches <joe@perches.com>]

On Mon, 2014-07-21 at 12:39 +0100, Lee Jones wrote:
> Hi Andy, Joe,

Hi Lee.

> When running checkpatch on drivers/mfd/tps80031.c I recieve the
> following warning:
> 
> > WARNING: Possible switch case/default not preceeded by break or
> >          fallthrough comment
> > #337: FILE: drivers/mfd/tps80031.c:337:
> > +       case TPS80031_BACKUP_REG:
> > 
> > total: 0 errors, 1 warnings, 573 lines checked
> 
> ... but we use switch statement fall through all the time when
> identifying different types of registers used with Regmap.  Placing a
> fall-through comment between them all sounds very messy to me.

Yes, it can be messy, but it's found some
actual bugs/defects.

> Also, the warning only fires on 'case's which do not use '...'
> notation, which seems a little odd.

That's a checkpatch defect.  Thanks for the report.

> Anyway, I'm not sure placing a 'fall through' comment makes the code
> any cleaner or reduces possible failure rate in any way.  Is there any
> chance that this check can be removed?

You could use the --ignore= cmd-line option or add it to
a .checkpatch.conf file.

$ ./scripts/checkpatch.pl -f drivers/mfd/tps80031.c  --ignore=missing_break
WARNING: Possible unnecessary 'out of memory' message
#435: FILE: drivers/mfd/tps80031.c:435:
+	if (!tps80031) {
+		dev_err(&client->dev, "Malloc failed for tps80031\n");

total: 0 errors, 1 warnings, 573 lines checked

NOTE: Ignored message types: MISSING_BREAK

drivers/mfd/tps80031.c has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.