linux-kernel - Re: [PATCH] Pinctrl: core: export pinctrl_provide

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACRpkdZtQkbGnQtb3DZf1XOVpbZgnBbqZD3kxEuCCAS4Pm3AGA@mail.gmail.com>
Date: Tue, 4 Nov 2025 11:49:20 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Gary Yang <gary.yang@...tech.com>
Cc: "robh@...nel.org" <robh@...nel.org>, "krzk+dt@...nel.org" <krzk+dt@...nel.org>, 
	"conor+dt@...nel.org" <conor+dt@...nel.org>, 
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>, 
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>, 
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, 
	"linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>, 
	cix-kernel-upstream <cix-kernel-upstream@...tech.com>, 
	"sfr@...b.auug.org.au" <sfr@...b.auug.org.au>
Subject: Re: [PATCH] Pinctrl: core: export pinctrl_provide_dummies() to fix
 build error

On Wed, Oct 29, 2025 at 4:35 AM Gary Yang <gary.yang@...tech.com> wrote:


> Generally a device may has two states: default state and sleep state. They are included in DTS file.
> So DTS has two nodes, one is for default state, and the other is for sleep state. When the device works, select
> default state, but select sleep state when the system enters str.

What is "str"? stand-by-retention? (Sorry for my ignorance.)

> There is two pinctrl controllers on CIX sky1. One is used under S0 state, and the other is used under S0 and S5 state.
> When enter str, the system enter S3 state and S0 domain power off. So the pinctrl controller under S0 state is also off.
> The settings for sleep state are loft and make no sense.
>
> But if we remove these settings, the pinctrl can't find sleep state and can't change state when system enter str.
> When resume pinctrl, pinctrl core may think state is still the same as before. So the settings can't be applied
> as expected.

Aha!

> To avoid write these unused settings in DTS file, we have to use pinctrl_provide_dummies() interface.
> Do you agree our schemes? What's your opinion? Please give us some suggestions. Thanks

I think it's fine to use the pinctrl dummies, I will draft a patch and
send so you can ACK it.

It's fun to get the whole picture of how this works on CIX silicon,
it's a new way of doing
things with two different pin controllers so I haven't seen this before!

Yours,
Linus Walleij