Re: [PATCH V2 1/4] pinctrl: imx: prepare for making "group_names" in "function_desc" const

[Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>]

On Wed, 2021-12-22 at 22:24 +0200, Abel Vesa wrote:
> On 21-12-16 17:22:03, Rafał Miłecki wrote:
> > From: Rafał Miłecki <rafal@xxxxxxxxxx>
> > 
> > The plan for "struct function_desc" is to make its "group_names"
> > /double/ const. That will allow drivers to use it with static const
> > data.
> > 
> > This imx change is required to avoid:
> > drivers/pinctrl/freescale/pinctrl-imx.c: In function 'imx_pinctrl_parse_functions':
> > drivers/pinctrl/freescale/pinctrl-imx.c:672:24: error: assignment of read-only location '*(func-
> > >group_names + (sizetype)(i * 4))'
> >   672 |   func->group_names[i] = child->name;
> >       |                        ^
> > 
> > Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
> > ---
> >  drivers/pinctrl/freescale/pinctrl-imx.c | 11 +++++++----
> >  1 file changed, 7 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c
> > index daf28bc5661d..47b2ab1a14d0 100644
> > --- a/drivers/pinctrl/freescale/pinctrl-imx.c
> > +++ b/drivers/pinctrl/freescale/pinctrl-imx.c
> > @@ -648,6 +648,7 @@ static int imx_pinctrl_parse_functions(struct device_node *np,
> >         struct device_node *child;
> >         struct function_desc *func;
> >         struct group_desc *grp;
> > +       const char **group_names;
> >         u32 i = 0;
> >  
> >         dev_dbg(pctl->dev, "parse function(%d): %pOFn\n", index, np);
> > @@ -663,14 +664,16 @@ static int imx_pinctrl_parse_functions(struct device_node *np,
> >                 dev_err(ipctl->dev, "no groups defined in %pOF\n", np);
> >                 return -EINVAL;
> >         }
> > -       func->group_names = devm_kcalloc(ipctl->dev, func->num_group_names,
> > -                                        sizeof(char *), GFP_KERNEL);
> > +
> > +       group_names = devm_kcalloc(ipctl->dev, func->num_group_names,
> > +                                  sizeof(char *), GFP_KERNEL);
> >         if (!func->group_names)
> This line needs to be:
>         if (!group_names)
> 
> Otherwise, the driver never probes successufully.

After my i.MX 8M Mini target running latest -next just hang early boot I bisected it to this commit.

I can confirm that this fixes it. Thanks!

> Linus, maybe you can squashed this fix in your tree without a resend.
> 
> >                 return -ENOMEM;
> > +       for_each_child_of_node(np, child)
> > +               group_names[i] = child->name;
> > +       func->group_names = group_names;
> >  
> >         for_each_child_of_node(np, child) {
> > -               func->group_names[i] = child->name;
> > -
> >                 grp = devm_kzalloc(ipctl->dev, sizeof(struct group_desc),
> >                                    GFP_KERNEL);
> >                 if (!grp) {
> > -- 
> > 2.31.1
-- 
Best regards - Mit freundlichen Grüssen - Meilleures salutations

Marcel Ziswiler
Software Team Lead - Embedded Linux BSP

Toradex AG
Ebenaustrasse 10 | 6048 Horw/Luzern | Switzerland | T: +41 41 500 4800