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=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED autolearn=ham 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 5C916C282D8 for ; Fri, 1 Feb 2019 19:06:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24DB9218FD for ; Fri, 1 Feb 2019 19:06:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fEczaGCU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730587AbfBATGo (ORCPT ); Fri, 1 Feb 2019 14:06:44 -0500 Received: from mail-lj1-f193.google.com ([209.85.208.193]:41617 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726506AbfBATGn (ORCPT ); Fri, 1 Feb 2019 14:06:43 -0500 Received: by mail-lj1-f193.google.com with SMTP id k15-v6so6722496ljc.8; Fri, 01 Feb 2019 11:06:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=QyUC6ELg9X4oIBfCTwPWnfdVJQ4lgZTskpCz7PW0qf8=; b=fEczaGCUnM0c+jyBdjHfSPoTbSuO3vRPdzYVLzw8FpKn2vscrCqaw9yXDCLbE1roIP TSi0MY2Q3Ys81tlGJuGzdh42BUHYiM7Z/skdAj22b0iXBiu+0LthgHTWmz1fW/d4x/1d MNg/y0RP8J1FgN32fOf1Joeg1theKuFIXL3OLgNB29Hnd9/4HI3rT1YhiK4Oud4u4P4t bz2Gk4PY54HiN08UriUtNmiplDVOxF1Ow0iYVz41GhecyaIh14sqiUQzRaVaP6++qacZ 3TuwspIquTgwJBu53u4ZAh/YF9dryiBZ4LGIkKP0IXexo6cwSAF90ZRl7FjWWDHDGClc 2Bpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=QyUC6ELg9X4oIBfCTwPWnfdVJQ4lgZTskpCz7PW0qf8=; b=VVEK9smLrxtAFCv38KgHXep8YrgD/E40ZBcF/PWqIu7vmXjQqpjjeOsX+xd9xSj7kU 20p5hd2zvT7XT6z87M13H47vxIwNRVbihEz9bn+sDWDn9leTXN7RBwBPHQ8I6f9tT2Ct Bhr57N7BmaMp1pOzSPmxyyyhm5HPvAEqLRQV9P+30OCClqATaLMk3Fh/Eig7wNkYngae CPLf1bgbt+v+faZcCuwyGQHAe3LZO8m9Zbi8PMXsGxQr03hXuIz7oRkc3c3bdZ8V8hda 3yF1W5tMoOR4+Lt+air2UQOEtXvkhtrPCktFLNf/OwhaZdnFC6jz/4VernA8VxE67DPi +wqw== X-Gm-Message-State: AJcUukdXcuztw1SxXjd4FAiZX7EDvOTK0FA5cKWSu6n7QMgyrV7QmIcS 21Qeo/mX7yNQ6QfqRkOiWau/oeMl X-Google-Smtp-Source: ALg8bN5H0StivNjl1miqpDu5rf5DSUNGSwxH5GuxWKqcxjZyIgbvP4lJXkQX6mz4+Nsyra34IEG63g== X-Received: by 2002:a2e:9849:: with SMTP id e9-v6mr32220167ljj.9.1549048000763; Fri, 01 Feb 2019 11:06:40 -0800 (PST) Received: from [192.168.2.145] (ppp91-79-175-49.pppoe.mtu-net.ru. [91.79.175.49]) by smtp.googlemail.com with ESMTPSA id s9-v6sm1429118lja.12.2019.02.01.11.06.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Feb 2019 11:06:40 -0800 (PST) Subject: Re: [PATCH V9 2/5] i2c: tegra: add bus clear master support To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, mkarthik@nvidia.com, smohammed@nvidia.com, talho@nvidia.com Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org References: <1549040867-18149-1-git-send-email-skomatineni@nvidia.com> <1549040867-18149-2-git-send-email-skomatineni@nvidia.com> From: Dmitry Osipenko Message-ID: Date: Fri, 1 Feb 2019 22:06:39 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <1549040867-18149-2-git-send-email-skomatineni@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 01.02.2019 20:07, Sowjanya Komatineni пишет: > Bus clear feature of Tegra I2C controller helps to recover from > bus hang when I2C master loses the bus arbitration due to the > slave device holding SDA LOW continuously for some unknown reasons. > > Per I2C specification, the device that held the bus LOW should > release it within 9 clock pulses. > > During bus clear operation, Tegra I2C controller sends 9 clock > pulses and terminates the transaction with STOP condition. > Upon successful bus clear operation, bus goes to idle state and > driver retries the transaction. > > Signed-off-by: Sowjanya Komatineni > Acked-by: Thierry Reding > --- > [V9] : Rebased to 5.0-rc4 > [V5/V6/V7/V8]: Same as V4 > [V4]: Added I2C Bus Clear support patch to this version of series. > > drivers/i2c/busses/i2c-tegra.c | 73 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 73 insertions(+) Reviewed-by: Dmitry Osipenko