From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id E40B9C44501 for ; Wed, 15 Jul 2026 10:20:49 +0000 (UTC) Received: from mx.nabladev.com (mx.nabladev.com [178.251.229.89]) by mx.groups.io with SMTP id smtpd.msgproc02-g2.3182.1784110840554626593 for ; Wed, 15 Jul 2026 03:20:40 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@nabladev.com header.s=dkim header.b=f9qiJEdy; spf=pass (domain: nabladev.com, ip: 178.251.229.89, mailfrom: pavel@nabladev.com) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id E0B89119B9E; Wed, 15 Jul 2026 12:20:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nabladev.com; s=dkim; t=1784110838; h=from:subject:date:message-id:to:cc:mime-version:content-type: in-reply-to:references; bh=ENvUFicvjl8BTigzEdJCDGf1TtHP3EUwcTexP+1HUWI=; b=f9qiJEdy7G7Wiorb1n2bBUeNqoNnh3ksQm+jCK7D4CNJ1dBQijYpc5TPYzyr276NnfI6bT TlnPsok+M1TJeDQreBCWQFaVNuqqwMrWyS6+ClSlBnUQYxT5CSoUhA1LCJE+MIW7l4Grgq Qh1jLc8Et2eH7FAaA6byD+otluLGaFrQUC0KJwaTUTRC7Yrz3y0Jd7xzMIwX1Dt5s1ckrV 5NFST80c1hw18+niGbaSQ1/ehEmPOFUjQgvmkVuisrfji7cFGtPMC1bFetVq3KfShhx6qW vcBM8Lz1iEbFcaLZ4mS0lOgj6NRjyuDw5kfr7NE0mGKL6P+rAfMWGT0kPPeoJQ== Date: Wed, 15 Jul 2026 12:20:36 +0200 From: Pavel Machek To: Biju Cc: cip-dev@lists.cip-project.org, Nobuhiro Iwamatsu , Pavel Machek , Biju Das , Lad Prabhakar Subject: Re: [PATCH 6.12.y-cip 14/23] mfd: syscon: Allow syscon nodes without a "syscon" compatible Message-ID: References: <20260703105923.251255-1-biju.das.jz@bp.renesas.com> <20260703105923.251255-15-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="4n+e0prY/np1qUVP" Content-Disposition: inline In-Reply-To: <20260703105923.251255-15-biju.das.jz@bp.renesas.com> X-Last-TLS-Session-Version: TLSv1.3 List-Id: X-Webhook-Received: from 45-33-107-173.ip.linodeusercontent.com [45.33.107.173] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Wed, 15 Jul 2026 10:20:49 -0000 X-Groupsio-URL: https://lists.cip-project.org/g/cip-dev/message/23591 --4n+e0prY/np1qUVP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > From: "Rob Herring (Arm)" >=20 > [ Upstream commit ba5095ebbc7a83965ac049a50fa493d7c751f19b ] >=20 > of_syscon_register_regmap() was added for nodes which need a custom > regmap setup. It's not really correct for those nodes to claim they are > compatible with "syscon" as the default handling likely doesn't work in > those cases. If device_node_get_regmap() happens to be called first, > then of_syscon_register() will be called and an incorrect regmap will be > created (barring some other error). That may lead to unknown results in > the worst case. In the best case, of_syscon_register_regmap() will fail > with -EEXIST. This problem remains unless these cases drop "syscon" (an > ABI issue) or we exclude them using their specific compatible. ATM, > there is only one user: "google,gs101-pmu" >=20 > There are also cases of adding "syscon" compatible to existing nodes > after the fact in order to register the syscon. That presents a > potential DT ABI problem. Instead, if there's a kernel change needing a > syscon for a node, then it should be possible to allow the kernel to > register a syscon without a DT change. That's only possible by using > of_syscon_register_regmap() currently, but in the future we may want to > support a match list for cases which don't need a custom regmap. >=20 > With this change, the lookup functions will succeed for any node > registered by of_syscon_register_regmap() regardless of whether the node > compatible contains "syscon". I note this is change to generic code. I trust it has all dependencies it needs and will not cause problems somewhere? Thanks and best regards, Pavel > +++ b/drivers/mfd/syscon.c > @@ -176,9 +176,12 @@ static struct regmap *device_node_get_regmap(struct = device_node *np, > break; > } > =20 > - if (!syscon) > - syscon =3D of_syscon_register(np, check_res); > - > + if (!syscon) { > + if (of_device_is_compatible(np, "syscon")) > + syscon =3D of_syscon_register(np, check_res); > + else > + syscon =3D ERR_PTR(-EINVAL); > + } > mutex_unlock(&syscon_list_lock); > =20 > if (IS_ERR(syscon)) > @@ -243,9 +246,6 @@ EXPORT_SYMBOL_GPL(device_node_to_regmap); > =20 > struct regmap *syscon_node_to_regmap(struct device_node *np) > { > - if (!of_device_is_compatible(np, "syscon")) > - return ERR_PTR(-EINVAL); > - > return device_node_get_regmap(np, true); > } > EXPORT_SYMBOL_GPL(syscon_node_to_regmap); --4n+e0prY/np1qUVP Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCalde9AAKCRAw5/Bqldv6 8op3AKCsnEtNnU+0ft7TQztPbfBDfrl31QCfQUUINyt2l5IpRmmlLjP4rZ/T2k0= =gDeW -----END PGP SIGNATURE----- --4n+e0prY/np1qUVP--