Re: [PATCH] pinctrl: aspeed: fix regmap error handling

[Andrew Jeffery <andrew@aj.id.au>]

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On Mon, 2016-09-12 at 10:52 +0930, Joel Stanley wrote:
> On Fri, Sep 9, 2016 at 6:56 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> > 
> > The newly added aspeed driver tries to check for a negative return
> > value from a pinctrl function, but stores the intermediate value in
> > a 'bool' variable, which cannot work:
> > 
> > drivers/pinctrl/aspeed/pinctrl-aspeed.c: In function 'aspeed_sig_expr_set':
> > drivers/pinctrl/aspeed/pinctrl-aspeed.c:192:11: error: comparison of constant '0' with boolean expression is always false [-Werror=bool-compare]
> > 
> > This slightly reworks the logic to use an explicit comparison with zero
> > before assigning to the temporary variable.
> Thanks for finding this Arnd.
> 
> Colin also found the issue. Thanks Colin!
> 
> I think we should take this version of the fix. Linus, can you put
> this in your tree please?

+1 on each point above.

I made a change to the loop body in response to feedback in one of the
earlier iterations and unfortunately this looks to have slipped past
me. I will look at adding a bit more static analysis to my patch
submission checklist!

> 
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Acked-by: Joel Stanley <joel@jms.id.au>

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>

> 
> Cheers,
> 
> Joel
> 
> > 
> > ---
> >  drivers/pinctrl/aspeed/pinctrl-aspeed.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/pinctrl/aspeed/pinctrl-aspeed.c b/drivers/pinctrl/aspeed/pinctrl-aspeed.c
> > index 7d461fc30d3c..0391f9f13f3e 100644
> > --- a/drivers/pinctrl/aspeed/pinctrl-aspeed.c
> > +++ b/drivers/pinctrl/aspeed/pinctrl-aspeed.c
> > @@ -187,10 +187,10 @@ static bool aspeed_sig_expr_set(const struct aspeed_sig_expr *expr,
> >                         continue;
> > 
> >                 ret = regmap_update_bits(map, desc->reg, desc->mask,
> > -                               pattern << __ffs(desc->mask));
> > +                               pattern << __ffs(desc->mask)) == 0;
> > 
> > -               if (ret < 0)
> > -                       return false;
> > +               if (!ret)
> > +                       return ret;
> >         }
> > 
> >         return aspeed_sig_expr_eval(expr, enable, map);
> > --
> > 2.9.0
> > 

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