linux-kernel - RE: [PATCH] pinctrl: renesas: rzg2l: Fix ISEL restore on resume

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Message-ID:
 <TY3PR01MB113469D5FBD53A8B507E5DC4A8609A@TY3PR01MB11346.jpnprd01.prod.outlook.com>
Date: Thu, 11 Sep 2025 13:39:04 +0000
From: Biju Das <biju.das.jz@...renesas.com>
To: Claudiu.Beznea <claudiu.beznea@...on.dev>, "geert+renesas@...der.be"
	<geert+renesas@...der.be>, "linus.walleij@...aro.org"
	<linus.walleij@...aro.org>
CC: "linux-renesas-soc@...r.kernel.org" <linux-renesas-soc@...r.kernel.org>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, Claudiu Beznea
	<claudiu.beznea.uj@...renesas.com>, "stable@...r.kernel.org"
	<stable@...r.kernel.org>
Subject: RE: [PATCH] pinctrl: renesas: rzg2l: Fix ISEL restore on resume

HI Caludiu,

> -----Original Message-----
> From: Claudiu Beznea <claudiu.beznea@...on.dev>
> Sent: 11 September 2025 14:24
> Subject: Re: [PATCH] pinctrl: renesas: rzg2l: Fix ISEL restore on resume
> 
> Hi, Biju,
> 
> On 9/11/25 13:43, Biju Das wrote:
> > Hi Claudiu,
> >
> >> -----Original Message-----
> >> From: Claudiu <claudiu.beznea@...on.dev>
> >> Sent: 08 September 2025 15:43
> >> Subject: [PATCH] pinctrl: renesas: rzg2l: Fix ISEL restore on resume
> >>
> >> From: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
> >>
> >> Commit 1d2da79708cb ("pinctrl: renesas: rzg2l: Avoid configuring ISEL
> >> in
> >> gpio_irq_{en,dis}able*()") dropped the configuration of ISEL from
> >> rzg2l_gpio_irq_enable()/rzg2l_gpio_irq_disable() and moved it to
> >> rzg2l_gpio_child_to_parent_hwirq()/rzg2l_gpio_irq_domain_free() to fix spurious IRQs.
> >>
> >> The resume code used rzg2l_gpio_irq_enable() (called from
> >> rzg2l_gpio_irq_restore()) to reconfigure the wakeup interrupts. Some
> >> drivers (e.g. Ethernet) may also reconfigure interrupts in their own
> >> code, eventually calling rzg2l_gpio_irq_enable(), when these are not wakeup interrupts.
> >>
> >> After commit 1d2da79708cb ("pinctrl: renesas: rzg2l: Avoid
> >> configuring ISEL in gpio_irq_{en,dis}able*()"), ISEL was no longer configured properly after resume.
> >>
> >> Fix this by adding rzg2l_gpio_irq_endisable() back into
> >> rzg2l_gpio_irq_enable(), and by using its unlocked variant in
> >> rzg2l_gpio_irq_restore(). Having IRQs enable in
> >> rzg2l_gpio_irq_enable() should be safe with respect to spurious IRQs,
> >> as in the probe case IRQs are enabled anyway in rzg2l_gpio_child_to_parent_hwirq(). No spurious IRQs
> were detected on suspend/resume tests (executed on RZ/G3S).
> >
> > IIRC, I believe the issue is ISEL is not restored during resume.
> 
> Yes
> 
> > Can we restore this register just like Schmitt register
> > suspend/restore[1]
> 
> The IA55 would have to be configured for interrupts as well. Doing it in other order will lead to
> spurious interrupts while resuming. The commit 254203f9a94c ("pinctrl: renesas: rzg2l: Add
> suspend/resume support") that introduced this approach, mentions the following:
> 
>     Because interrupt signals are routed to IA55 interrupt controller and
>     IA55 interrupt controller resumes before pin controller, patch restores
>     also the configured interrupts just after pin settings are restored to
>     avoid invalid interrupts while resuming.

OK. So enable/disable Keep ISEL configuration as it is, so the pin gpio int always.
Which commit 1d2da79708cb ("pinctrl: renesas: rzg2l: Avoidconfiguring ISEL in gpio_irq_{en,dis}able*()")
is doing.

The new addition is suspend/resume restores ISEL along with reconfiguring interrupts.

Is it correct?

Cheers,
Biju