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 X-Spam-Level: X-Spam-Status: No, score=-9.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64BCFC4727D for ; Mon, 5 Oct 2020 08:16:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08EE920776 for ; Mon, 5 Oct 2020 08:16:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601885807; bh=Y+4/OTAGP1UzABKUO+6NPw0ZwNRfR0vGq0IKYFkmjrc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=F98yhe24qPeiJOZowEq0kus13g+IwFeCb7OC9UznhaBSZVilDTI35LxG1z5fNB8Nm lMDJ6mlNkLctHnCKJmDiZtoZJyX91UW8BaOaIrFeSLizreZo2G0tf8hqWWkP6UXvhw w2Qr6TA6NxWjryzlWswDqV+Agwvt6Pj8FoSU9g7Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725970AbgJEIQq (ORCPT ); Mon, 5 Oct 2020 04:16:46 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:55265 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725880AbgJEIQp (ORCPT ); Mon, 5 Oct 2020 04:16:45 -0400 Received: by mail-wm1-f65.google.com with SMTP id p15so3132612wmi.4; Mon, 05 Oct 2020 01:16:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=so3Q2iStLANQzUsWPJtNOkoc+zx5z4LsFtN/g7RdwuA=; b=Yb1QZxxkooLudEnk8XN6HPSfmEsrM9EL59bf2/392ELo2GDinoakbX9PgcBJjbI5st xxr3lcdNiWhjHtghgEAjwQmyfe3aCWtaJM+mMO4K3BX3d6Z5eaU5jx0W8ZR8/jvSffEd XnjVHyd0XkQ6BUR6kMQvm394XVa1oQbQCWldRigxltOR4n5chjMbPaFzW3poN+YQpiaJ qU4j9kmCxMjyaz0O4K/i0PK9lNDkjHuVRackFUekA/AQ2oiGGdHe1dAI+vWkIFpy0FZR /Z97mF9MMchmOqxVu0nsqhsnao2HzD+O/X+RlxAnuBman4qgU7I0qp0nadjm2MSRR6r6 J8+A== X-Gm-Message-State: AOAM533YN76uQDYP+/GNqwOsIgQGnJlbpTONyxXdszuZTbsU6iH3/uBT /ajAyb3efunjvk5Se8ndjTw= X-Google-Smtp-Source: ABdhPJy1FDIel9WhtFJmJd9CyAQEOlK6fIY5XuLZ0pflqjU2ZvCyXQDazBGV4roSAtjoCmXu+DoPFw== X-Received: by 2002:a1c:4b0f:: with SMTP id y15mr16442283wma.165.1601885803104; Mon, 05 Oct 2020 01:16:43 -0700 (PDT) Received: from kozik-lap ([194.230.155.194]) by smtp.googlemail.com with ESMTPSA id c130sm873401wma.17.2020.10.05.01.16.41 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 05 Oct 2020 01:16:41 -0700 (PDT) Date: Mon, 5 Oct 2020 10:16:39 +0200 From: Krzysztof Kozlowski To: Christian Eggers Cc: Oleksij Rempel , Shawn Guo , Sascha Hauer , Fabio Estevam , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Pengutronix Kernel Team , NXP Linux Team , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2 3/3] i2c: imx: Don't generate STOP condition if arbitration has been lost Message-ID: <20201005081639.GA7431@kozik-lap> References: <20201002152305.4963-1-ceggers@arri.de> <20201002152305.4963-4-ceggers@arri.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201002152305.4963-4-ceggers@arri.de> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 02, 2020 at 05:23:05PM +0200, Christian Eggers wrote: > If arbitration is lost, the master automatically changes to slave mode. > I2SR_IBB may or may not be reset by hardware. Raising a STOP condition > by resetting I2CR_MSTA has no effect and will not clear I2SR_IBB. > > So calling i2c_imx_bus_busy() is not required and would busy-wait until > timeout. > > Signed-off-by: Christian Eggers > Cc: stable@vger.kernel.org # Requires trivial backporting, simple remove > # the 3rd argument from the calls to > # i2c_imx_bus_busy(). > --- > drivers/i2c/busses/i2c-imx.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > Tested (not extensively) on Vybrid VF500 (Toradex VF50): Tested-by: Krzysztof Kozlowski The I2C on Vybrid VF500 still works fine (also bigger transfers). I did not test this actual condition (arbitration) but only a regular I2C driver (BQ27xxx fuel gauge). Obviously this only proves that regular operation is not broken... Best regards, Krzysztof