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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 83AEEC28CC0 for ; Thu, 30 May 2019 11:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5989724298 for ; Thu, 30 May 2019 11:27:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZmxKCWRr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726454AbfE3L1e (ORCPT ); Thu, 30 May 2019 07:27:34 -0400 Received: from mail-lf1-f66.google.com ([209.85.167.66]:41462 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725440AbfE3L1e (ORCPT ); Thu, 30 May 2019 07:27:34 -0400 Received: by mail-lf1-f66.google.com with SMTP id 136so4728984lfa.8; Thu, 30 May 2019 04:27:32 -0700 (PDT) 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=JENy3lopc80MuuiSTYnGTbQpOx3WqOUAndzP5hkjx4w=; b=ZmxKCWRrz772eNoIL9TX0K3sGashtoYX5uOJp2C3SxKFtNwWHviuIyyVM27VV8EUAc 6JzDONOGIMSpa91cqdy1Ia28gt5UpF1DM36qH5Zi29Dnbeh1EuaEEDSvzcM4RGQWiK+o s9kiRxd+55flyoBu43by+e7FpZ7KmYGy+/GpyXHB+VjfTihSbh+pHhHOrh59aMNJsrn3 9wAngvmmzrwFM/FYwMHPid+RxbUhoONswax/4cQ1MgWJMpgzNJFh9vkhcRuV/e/yjER5 A0iSX12zYze0fOuKcKdYHul/g53iy7DrtYePXCPsVO14kxWmI7DeUhTk2tYClGOWjge5 zEOQ== 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=JENy3lopc80MuuiSTYnGTbQpOx3WqOUAndzP5hkjx4w=; b=iPkslVXGN79rc0pngp/J6KSXZCAB9GVyiU9QjAV81+AbGyaO8FmmRyUjO5K697EpF+ 2MQPwIQI76wrieGoH3a9hSpME297WeTnu5CABq/HxMxrJxdxWa6dTBPSbnhMo0qG+AWm eCyj4je4Eg+gknTI1WqN52O6aK0470qF4FVRZZNQWgJGclIiKEOWlVcvTywLdDw+xNQf PeMrDawThJ94qO8XVrn9BQlnI+CfnhojU3+tjI9u27qEEEQnYp9eVOJZh5FR7Hb693jF EocaOeZQQgj8TTY7WGpSEKNuWu4bEehA8Lwy+xtxEsCApbT++zqGJSx2TsuO6S3u47JT so0w== X-Gm-Message-State: APjAAAWZAo+NCvX0M5r52MocUK8uGe/CJW/5IbaLhEb7tRF4q1tbjrLK lrKibOa3nIQA+6y+hAu6dxkq2HKS X-Google-Smtp-Source: APXvYqwTSfyXXvpfDT8aiAY/fiws1afRBScx7FfoqwY3K0Gu+QtxuoAsy0swpn2Y4fWUmFFcH92JfQ== X-Received: by 2002:a19:7905:: with SMTP id u5mr1815085lfc.117.1559215652093; Thu, 30 May 2019 04:27:32 -0700 (PDT) Received: from [192.168.2.145] ([94.29.35.141]) by smtp.googlemail.com with ESMTPSA id u13sm440578lfm.16.2019.05.30.04.27.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 30 May 2019 04:27:31 -0700 (PDT) Subject: Re: [PATCH V1] i2c: busses: tegra: Add suspend-resume support To: Bitan Biswas , Laxman Dewangan , Thierry Reding , Jonathan Hunter , linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Shardar Mohammed , Sowjanya Komatineni , Mantravadi Karthik References: <1559195718-6693-1-git-send-email-bbiswas@nvidia.com> From: Dmitry Osipenko Message-ID: Date: Thu, 30 May 2019 14:27:30 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <1559195718-6693-1-git-send-email-bbiswas@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 30.05.2019 8:55, Bitan Biswas пишет: > Post suspend I2C registers have power on reset values. Before any > transfer initialize I2C registers to prevent I2C transfer timeout > and implement suspend and resume callbacks needed. Fix below errors > post suspend: > > 1) Tegra I2C transfer timeout during jetson tx2 resume: > > [ 27.520613] pca953x 1-0074: calling pca953x_resume+0x0/0x1b0 @ 2939, parent: i2c-1 > [ 27.633623] tegra-i2c 3160000.i2c: i2c transfer timed out > [ 27.639162] pca953x 1-0074: Unable to sync registers 0x3-0x5. -110 > [ 27.645336] pca953x 1-0074: Failed to sync GPIO dir registers: -110 > [ 27.651596] PM: dpm_run_callback(): pca953x_resume+0x0/0x1b0 returns -110 > [ 27.658375] pca953x 1-0074: pca953x_resume+0x0/0x1b0 returned -110 after 127152 usecs > [ 27.666194] PM: Device 1-0074 failed to resume: error -110 > > 2) Tegra I2C transfer timeout error on jetson Xavier post resume. > > Signed-off-by: Bitan Biswas > --- > drivers/i2c/busses/i2c-tegra.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c > index ebaa78d..f6a377f 100644 > --- a/drivers/i2c/busses/i2c-tegra.c > +++ b/drivers/i2c/busses/i2c-tegra.c > @@ -1687,9 +1687,33 @@ static int tegra_i2c_remove(struct platform_device *pdev) > } > > #ifdef CONFIG_PM_SLEEP > +static int tegra_i2c_suspend(struct device *dev) > +{ > + struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); > + > + i2c_mark_adapter_suspended(&i2c_dev->adapter); > + > + return 0; > +} > + > +static int tegra_i2c_resume(struct device *dev) > +{ > + struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); > + int ret; > + > + i2c_lock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER); > + ret = tegra_i2c_init(i2c_dev, false); > + i2c_unlock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER); Why the locking is needed here? > + if (!ret) > + i2c_mark_adapter_resumed(&i2c_dev->adapter); > + > + return ret; A very minor nit.. will be a bit more straightforward to write this as: int err; err = tegra_i2c_init(i2c_dev, false); if (err) return err; i2c_mark_adapter_resumed(&i2c_dev->adapter); return 0; It is always cleaner to return 0 on success. -- Dmitry