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References: <20240530173857.164073-1-prabhakar.mahadev-lad.rj@bp.renesas.com> <20240530173857.164073-15-prabhakar.mahadev-lad.rj@bp.renesas.com>
In-Reply-To: <20240530173857.164073-15-prabhakar.mahadev-lad.rj@bp.renesas.com>
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Wed, 5 Jun 2024 14:32:53 +0200
Message-ID: <CAMuHMdU5tYSF7m435F=sBS0FjoZ=q7D4RsufRYLbNVzKArUYPQ@mail.gmail.com>
Subject: Re: [PATCH v3 14/15] pinctrl: renesas: pinctrl-rzg2l: Acquire lock in rzg2l_pinctrl_pm_setup_pfc()
To: Prabhakar <prabhakar.csengg@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>, Rob Herring <robh@kernel.org>, 
	Krzysztof Kozlowski <krzk+dt@kernel.org>, Conor Dooley <conor+dt@kernel.org>, 
	Magnus Damm <magnus.damm@gmail.com>, linux-renesas-soc@vger.kernel.org, 
	linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, 
	linux-kernel@vger.kernel.org, Biju Das <biju.das.jz@bp.renesas.com>, 
	Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>, 
	Fabrizio Castro <fabrizio.castro.jz@renesas.com>, 
	Paul Barker <paul.barker.ct@bp.renesas.com>, 
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
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On Thu, May 30, 2024 at 7:42=E2=80=AFPM Prabhakar <prabhakar.csengg@gmail.c=
om> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> To keep consistency with rzg2l_pinctrl_set_pfc_mode(), acquire the lock
> in rzg2l_pinctrl_pm_setup_pfc() during PFC setup.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> v2->v3
> - New patch

Thanks for your patch!

> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> @@ -2541,7 +2541,9 @@ static void rzg2l_pinctrl_pm_setup_dedicated_regs(s=
truct rzg2l_pinctrl *pctrl, b
>  static void rzg2l_pinctrl_pm_setup_pfc(struct rzg2l_pinctrl *pctrl)
>  {
>         u32 nports =3D pctrl->data->n_port_pins / RZG2L_PINS_PER_PORT;
> +       unsigned long flags;
>
> +       spin_lock_irqsave(&pctrl->lock, flags);
>         pctrl->data->pwpr_pfc_lock_unlock(pctrl, false);
>
>         /* Restore port registers. */
> @@ -2586,6 +2588,7 @@ static void rzg2l_pinctrl_pm_setup_pfc(struct rzg2l=
_pinctrl *pctrl)
>         }
>
>         pctrl->data->pwpr_pfc_lock_unlock(pctrl, true);
> +       spin_unlock_irqrestore(&pctrl->lock, flags);
>  }
>
>  static int rzg2l_pinctrl_suspend_noirq(struct device *dev)

It's definitely safer to unlock only while holding the lock.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--=20
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k=
.org

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
                                -- Linus Torvalds