linux-kernel - Re: [PATCH v2 1/3] clk: renesas: rzg2l-cpg: Use GENPD_FLAG

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Message-ID: <CAMuHMdX+Q99MvQRZcwGbk8F8SiAUzRU_t2QmRuO_6etAqqXskg@mail.gmail.com>
Date: Thu, 29 Aug 2024 14:32:49 +0200
From: Geert Uytterhoeven <geert@...ux-m68k.org>
To: Claudiu <claudiu.beznea@...on.dev>
Cc: mturquette@...libre.com, sboyd@...nel.org, wim@...ux-watchdog.org, 
	linux@...ck-us.net, ulf.hansson@...aro.org, linux-renesas-soc@...r.kernel.org, 
	linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-watchdog@...r.kernel.org, linux-pm@...r.kernel.org, 
	Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
Subject: Re: [PATCH v2 1/3] clk: renesas: rzg2l-cpg: Use GENPD_FLAG_* flags
 instead of local ones

Hi Claudiu,

On Wed, Aug 28, 2024 at 4:06 PM Claudiu <claudiu.beznea@...on.dev> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
>
> For watchdog PM domain it is necessary to provide GENPD_FLAG_IRQ_SAFE flag
> to be able to power on the watchdog PM domain from atomic context. For
> this, adjust the current infrastructure to be able to provide GENPD_FLAG_*
> for individual PM domains.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>

Thanks for your patch!

> --- a/drivers/clk/renesas/rzg2l-cpg.c
> +++ b/drivers/clk/renesas/rzg2l-cpg.c
> @@ -1680,11 +1680,13 @@ static int rzg2l_cpg_power_off(struct generic_pm_domain *domain)
>         return 0;
>  }
>
> -static int __init rzg2l_cpg_pd_setup(struct rzg2l_cpg_pd *pd, bool always_on)
> +static int __init rzg2l_cpg_pd_setup(struct rzg2l_cpg_pd *pd, u32 genpd_flags,
> +                                    bool always_on)

You don't need always_on, as that should already be reflected in
genpd_flags.

Also, you could do without passing genpd_flags, if the caller would have
initialized pd->genpd.flags (it already initializes pd->genpd.name).

>  {
>         struct dev_power_governor *governor;
>
> -       pd->genpd.flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
> +       pd->genpd.flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP |
> +                          genpd_flags;

Change not needed if the caller would have initialized flags.

>         pd->genpd.attach_dev = rzg2l_cpg_attach_dev;
>         pd->genpd.detach_dev = rzg2l_cpg_detach_dev;
>         if (always_on) {

The next line is

    pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;

which should already be the case if always_on is true, so it can
be removed.

> @@ -1712,7 +1714,7 @@ static int __init rzg2l_cpg_add_clk_domain(struct rzg2l_cpg_priv *priv)
>
>         pd->genpd.name = np->name;

pd->genpd.flags = GENPD_FLAG_ALWAYS_ON;

>         pd->priv = priv;
> -       ret = rzg2l_cpg_pd_setup(pd, true);
> +       ret = rzg2l_cpg_pd_setup(pd, 0, true);

s/0/GENPD_FLAG_ALWAYS_ON/, FWIW ;-)

>         if (ret)
>                 return ret;
>
> @@ -1777,7 +1779,8 @@ static int __init rzg2l_cpg_add_pm_domains(struct rzg2l_cpg_priv *priv)
>                 return ret;
>
>         for (unsigned int i = 0; i < info->num_pm_domains; i++) {
> -               bool always_on = !!(info->pm_domains[i].flags & RZG2L_PD_F_ALWAYS_ON);
> +               u32 genpd_flags = info->pm_domains[i].genpd_flags;
> +               bool always_on = !!(genpd_flags & GENPD_FLAG_ALWAYS_ON);
>                 struct rzg2l_cpg_pd *pd;
>
>                 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
> @@ -1789,7 +1792,7 @@ static int __init rzg2l_cpg_add_pm_domains(struct rzg2l_cpg_priv *priv)

You can add

    pd->genpd.flags = info->pm_domains[i].genpd_flags;

above.

>                 pd->id = info->pm_domains[i].id;
>                 pd->priv = priv;
>
> -               ret = rzg2l_cpg_pd_setup(pd, always_on);
> +               ret = rzg2l_cpg_pd_setup(pd, genpd_flags, always_on);
>                 if (ret)
>                         return ret;

What about moving the conditional call to rzg2l_cpg_power_on()
below to rzg2l_cpg_pd_setup()? Then this function no longer needs
the always_on flag.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

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