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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DA557C433F5 for ; Fri, 28 Jan 2022 10:39:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Reply-To:Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date :Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=NB8qZLMZBfMPaMtT00J2Ppoi1Y+MDX1O7MX2E/RTKEE=; b=GKdnETLz1j9seqtkLDmHIwC5GK pTpOA7C68NGUgg6HFA+EMuA51ctUd8lM5FYBK1jr9+0jcvFZZNaB7SWkI/Gp75wOM2UtXHSU5vDZV hyRoe4focVyf5X6CJOkzOoC/Yl7f7m+q28QRznnx6rM60qRkV4bPateaLdxotF11LRUb5PAAtVV5q hMEqYohSbz8N27ChQ3JuGHNpUw3wwNl10knF4jU/ns7aXR1fzCiQDufv05zSAxvXm0ArD7JTCfEqD WCNu07tMQ54gs/tNwfoCmvR1HcvAv9cWPCont+Ek5ALxdR8YGSAAxyMeNWyixt/oJ0YzIovnQQnAt xX2xf+Yg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nDOdY-001Wj2-Cc; Fri, 28 Jan 2022 10:37:49 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nDOdQ-001WiK-Ot for linux-arm-kernel@lists.infradead.org; Fri, 28 Jan 2022 10:37:43 +0000 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 dfw.source.kernel.org (Postfix) with ESMTPS id BD1BB61E76; Fri, 28 Jan 2022 10:37:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D1E5C340E0; Fri, 28 Jan 2022 10:37:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643366259; bh=Uy+++PWtPa7zd1qw+wNw6uYGotVQJL/yndlPtdBNAKA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PQkofFD8DV9FsWWisPsOGCebQWLmXohOa6g5KLqDjfD/kM3agoP5q9+pUnf1JDK5k r3cQeKDzXXLXEVNL5UYeQFwdQeCnkl1nELVsDPnXcOPLJEfiisq58Btqvevnt+8d07 oR+qKMSGb+4PRVht+IWSGXnkDFtj0RfQwgZ2/LLW95FERP5XXiUvsUkzJKZLc8F9o5 w/HBTEvJ7A+kXJ9AZn/eW8mseIO3vo4e9Z51OZAml9PR1T9/OBqOSPkUbAlvz0Mw5A NwSgiV7MZCQKo452jqnctnVbEqnAWQK8xlrz0DUZJmGBzmHkANur5t3hAxm8rQSPGH JN+q7gKk8C9xg== Date: Fri, 28 Jan 2022 11:37:31 +0100 From: Wolfram Sang To: "Ivan T. Ivanov" Cc: Florian Fainelli , Ray Jui , Scott Branden , Nicolas Saenz Julienne , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Phil Elwell Subject: Re: [PATCH] i2c: bcm2835: Set clock-stretch timeout to 35ms Message-ID: Mail-Followup-To: Wolfram Sang , "Ivan T. Ivanov" , Florian Fainelli , Ray Jui , Scott Branden , Nicolas Saenz Julienne , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Phil Elwell References: <20220117102504.90585-1-iivanov@suse.de> MIME-Version: 1.0 In-Reply-To: <20220117102504.90585-1-iivanov@suse.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220128_023741_677565_B1AA6581 X-CRM114-Status: GOOD ( 14.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============4579131370737133855==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============4579131370737133855== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="tNNl2xM7+YgU3NMO" Content-Disposition: inline --tNNl2xM7+YgU3NMO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Ivan, > The BCM2835 I2C blocks have a register to set the clock-stretch > timeout - how long the device is allowed to hold SCL low - in bus > cycles. The current driver doesn't write to the register, therefore > the default value of 64 cycles is being used for all devices. >=20 > Set the timeout to the value recommended for SMBus - 35ms. By default, busses are I2C and not SMBus, so it looks like we should finally apply this patch which disables CLKT: http://patchwork.ozlabs.org/project/linux-i2c/patch/1519422151-6218-1-git-s= end-email-stefan.wahren@i2se.com/ If you really want the SMBus timeout applied, you can check for a "smbus" property in DT and then set CLKT accordingly in a seperate patch. Kind regards, Wolfram --tNNl2xM7+YgU3NMO Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmHzx2cACgkQFA3kzBSg KbbiUhAAibR16ghawqi+04Dq+II/mrR+2C1nKSZduVNKyzZOtw93Z5X4LS213VTU geHA1RE+OoWG4sIMRijjvMGuYoyF/3F/czyoMBUGFyJZpWtQCz/iRj+nNmJBG3l3 Bqd1SeAAWc0ePewgTe3j4024Yn/v1RddUAgXsZ7JFmgQqy3APMdTo5WzfXoTAa4X S+hh52VN1+hlIx3bqlfna29JrQPU1aH+fggqHJkC2L7TZQs0NVFzq0kkAcQqn3gO VHEHFTlXDQPLe1Wncha7fs1ADx8pNdmd55YFer/FCPEqtvxn5RCJltDzojWhG11P vWjJCmmJAy4uqeYjx8QE6jGnKW6rZWCTalru5A2NB8hci+vuoxqEBpzM9QtESdIJ CFpSLtg9lJx29s0rrG6ixu+3YJ5j85TEwGTHrtBi2J+GjFYdDnCl9/Yhl6gjgrwI IETqYZLCv4vAflVzc8zbo4gzthdcB4CHRiD8FfHRP5iqT+JAg6a9i4mT82cLVX6y zUyhWJAPV2QlVUN6rHR1zU4bTcCqymkyxbl7KRZNUuE0O+/1k2AIBzeHLXq4292u 5baiB0EJ0xs7z24OOhkReAuXbsWo4x8HY9dSLgrkTZGkfRyioS+SU/h3P7Hzf7IO L8IaGZgUEzxRvspuFFuQfcvkiQStWiLcoiJW8mjdCe03sF2MKOQ= =SuZW -----END PGP SIGNATURE----- --tNNl2xM7+YgU3NMO-- --===============4579131370737133855== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============4579131370737133855==--