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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98DFDC433EF for ; Sat, 14 May 2022 14:26:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233219AbiENO00 (ORCPT ); Sat, 14 May 2022 10:26:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233050AbiENO0Z (ORCPT ); Sat, 14 May 2022 10:26:25 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DA7EDF48; Sat, 14 May 2022 07:26:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id C600CCE0ABA; Sat, 14 May 2022 14:26:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 452CCC340EE; Sat, 14 May 2022 14:26:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652538381; bh=ToD809RuY6hiXX+oncfqN67gVFXAQVrADjiQjJV3dEI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i65GwFOC0zB83eUL9/lR2auEhM9UrNTQT2dN75bb0bl90eK/Bx5DTmmt2nDK4dsRP b3SvvU9TskXzHzbOUK1e/oIuaVJhJwBQT3Yy7EIRL+7OBjFafG5TKHpAv8oWKGOvP4 E4a84GMXmT2I8LRhA04FSdNw2JJBf7ocBTB7JbLPHyY0Czp6APaLGtIVpEXia65z9C Ha2Q1sAr6UNntams5ZDpedtIzbVH11PbMLdtMqxyh8BCokqvSaWZnu5t0tMIN/gTpi bNXTG/LUOGL/hg02MAlq401zTCLeqF76C68zt3W7L4MESAVjfZnB8FnQSFh9Wh9w99 qxfVnJoruzCuw== Date: Sat, 14 May 2022 16:26:16 +0200 From: Wolfram Sang To: Vincent Whitchurch Cc: kernel@axis.com, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, krzk+dt@kernel.org, robh+dt@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] dt-bindings: i2c: add property to avoid device detection Message-ID: Mail-Followup-To: Wolfram Sang , Vincent Whitchurch , kernel@axis.com, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, krzk+dt@kernel.org, robh+dt@kernel.org, linux-kernel@vger.kernel.org References: <20220412085046.1110127-1-vincent.whitchurch@axis.com> <20220412085046.1110127-2-vincent.whitchurch@axis.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="NL3Sz6YKj32sHoBj" Content-Disposition: inline In-Reply-To: <20220412085046.1110127-2-vincent.whitchurch@axis.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --NL3Sz6YKj32sHoBj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 12, 2022 at 10:50:45AM +0200, Vincent Whitchurch wrote: > When drivers with ->detect callbacks are loaded, the I2C core does a > bunch of transactions to try to probe for these devices, regardless of > whether they are specified in the devicetree or not. (This only happens > on I2C controllers whose drivers enable the I2C_CLASS* flags, but this > is the case for generic drivers like i2c-gpio.) >=20 > These kinds of transactions are unnecessary on systems where the > devicetree specifies all the devices on the I2C bus, so add a property > to indicate that the devicetree description of the hardware is complete > and thus allow this discovery to be disabled. Hmm, I don't think the name is fitting. "no-detect" is the desired behaviour but a proper description is more like "bus-complete" or something? That aside, I am not sure we should handle this at DT level. Maybe we should better change the GPIO driver to not populate a class if we have a firmware node? --NL3Sz6YKj32sHoBj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmJ/vAQACgkQFA3kzBSg KbbFog/9Gv3IJ+MHl6N3qQ0ieQcG5+wD+BO8/McbKQuR+2LqOOd8LVx5TV1+5czC +Ef69jO9ch6vV5T9WVrnErF4h1wtGiK5HF/1AnMjagTXtNNIaxbyEOBvowY4hVUM E58vzkrlZNIKY+147vnatDWw670DOTAP6GvvKg4cfGSK0ZXxRGkuXzWreYM9seJD V1L9EpBDEZ80Y6RYJbWzExPyslGja8avFLzOqy5Q4dvsHnB8P7Mq6jrQXB6bqNWQ hakv42huhY+WzplBlqNpfUiqGOC/5C71s17g8NKQ5BZfjV+HSO9L1ueHgFsOpWS7 6PEj8o2t+GJagce4TZJ2ofi7YrJNRNemxK9uLNwmdmmcLFZCTBxn/3/rZQotCPzu VM9HDgnNQhdavit/Sqw9Vq89oeAq9QGbj/FWCTIELbmToVE0d3ufuWaLnDPctLW9 TzWV2C/B/zjDtglZmg1fjJI5nr38l7qpWbhd95rzxO1vsYSXTwYRYfOIGukgDNlj gURWV+df7I89Rc6DL9ZSM5qu0h7iqmZLbE3RAnqrYjdr7AVXVqq2rmu0r0VjkzYw 6rzr4BN6oWPrthHLWOCsz4uCIeO802Vj5hkXqKRf8SrhkyoQFTv1H3RrSQ/F/qmV diN/c0v5IqmndTctQau7yl+AuCgj9wJ8M32Zb6N+ZZuyXQr+EEU= =AA2G -----END PGP SIGNATURE----- --NL3Sz6YKj32sHoBj--