Re: [RFC v3 1/2] pinctrl: core: Add pinctrl_mux_gpio_request_enable

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Fabrizio,

On Thu, Dec 6, 2018 at 10:47 AM Fabrizio Castro
<fabrizio.castro@xxxxxxxxxxxxxx> wrote:
> > From: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > Sent: 05 December 2018 21:46
> > Subject: Re: [RFC v3 1/2] pinctrl: core: Add pinctrl_mux_gpio_request_enable
> >
> > On Tue, Nov 20, 2018 at 4:19 PM Fabrizio Castro
> > <fabrizio.castro@xxxxxxxxxxxxxx> wrote:
> >
> > > Sometimes there is the need to change the muxing of a pin to make it
> > > a GPIO without going through gpiolib.
> > > This patch adds pinctrl_mux_gpio_request_enable to deal with this new
> > > use case from code that has nothing to do with pinctrl.
> >
> > It has a lot to do with pinctrl I think, so I get confused by this
> > commit message.
>
> I can improve that
>
> >
> > >  extern int pinctrl_gpio_request(unsigned gpio);
> > > +extern int pinctrl_mux_gpio_request_enable(unsigned gpio);
> >
> > What's wrong with just using the existing call
> > pinctrl_gpio_request() right above your new one?
> >
> > It's not like we're reference counting or something, it's just
> > a callback. Sprinkle some comments to show what's going
> > on.
>
> I tried that, and it was working for me, then something changed lately
> in gpiolib that broke that solution, and Geert picked it up on his end.
> Please see this:
> https://patchwork.kernel.org/patch/10671325/
>
> This patch was made to overcome the problems of the previous patch.
>
> >
> > If you for some reason need a new call for this specific
> > use case, it needs to be named after the use case,
> > like pinctrl_gpio_request_for_irq()
> > so it is obvious what the function is doing.
>
> I can do that, but I would like to hear from Geert first, no point in going
> around in circle if this solution is not acceptable to him.
>
> Geert, what do you think?

/me gives v3 a try on Koelsch, Salvator-XS, and Ebisu-4D:

    BUG: sleeping function called from invalid context

for mmc, adv7511, gpio-keys, and Ethernet PHY.

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds