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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 E3E10C04AB5 for ; Thu, 6 Jun 2019 13:59:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B83E220868 for ; Thu, 6 Jun 2019 13:59:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="DRtQGgpR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728644AbfFFN7B (ORCPT ); Thu, 6 Jun 2019 09:59:01 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:3899 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727176AbfFFN7A (ORCPT ); Thu, 6 Jun 2019 09:59:00 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 06 Jun 2019 06:58:57 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 06 Jun 2019 06:58:59 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 06 Jun 2019 06:58:59 -0700 Received: from [10.19.65.14] (172.20.13.39) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 6 Jun 2019 13:58:56 +0000 Subject: Re: [PATCH V2] i2c: busses: tegra: Add suspend-resume support To: Dmitry Osipenko , Laxman Dewangan , Thierry Reding , Jonathan Hunter , , , CC: Shardar Mohammed , Sowjanya Komatineni , Mantravadi Karthik References: <1559800475-5446-1-git-send-email-bbiswas@nvidia.com> From: Bitan Biswas Message-ID: <5871f51b-11d4-8bc9-6f40-4a91f2aab8f8@nvidia.com> Date: Thu, 6 Jun 2019 06:58:53 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1559829537; bh=jpr983eo6FR4Yd08yaKIZZG/M2mk3OEaK2jrPUrtJsA=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=DRtQGgpRwwQvoV1jn1wXUXplwdgLlkbVWodLf/zfqBOa/KxIHCcR0l6tu11B2U97j +lxuv9nPEEhzulbtaYHaT6lVZsmWrZzFcxTSbUIkLa7HYBsC9G+a/KNaA4xMsUkyD9 wUFCpw+KClh4n7HLAQzRhJA+kPKi2SXw5JO9fuVYuYsoASDjrq9E4fMuUjzd6J2jYz C0EfeCHve0tNTTPm2vTyu5S6wYrqPyekcT3fG3o0JL3au/+z/A2wOzIpGdxGarlore cfFoyGwgZDrgGbXTTEXZyqtuz6vwOHHnWQvaYwYe9YtC8HwhrDOMImqKIjoCs+AT9a titkOOCvf8bGw== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/6/19 5:06 AM, Dmitry Osipenko wrote: > 06.06.2019 8:54, Bitan Biswas =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> 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 af= ter 127152 usecs >> [ 27.666194] PM: Device 1-0074 failed to resume: error -110 >> >> 2) Tegra I2C transfer timeout error on jetson Xavier post resume. >> >> Remove i2c bus lock-unlock calls in resume callback as i2c_mark_adapter_= * >> (suspended-resumed) help ensure i2c core calls from client are not >> executed before i2c-tegra resume. >> >> Signed-off-by: Bitan Biswas >> --- >> drivers/i2c/busses/i2c-tegra.c | 23 +++++++++++++++++++++++ >> 1 file changed, 23 insertions(+) >> >> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-teg= ra.c >> index ebaa78d..76b7926 100644 >> --- a/drivers/i2c/busses/i2c-tegra.c >> +++ b/drivers/i2c/busses/i2c-tegra.c >> @@ -1687,7 +1687,30 @@ static int tegra_i2c_remove(struct platform_devic= e *pdev) >> } >> =20 >> #ifdef CONFIG_PM_SLEEP >> +static int tegra_i2c_suspend(struct device *dev) >> +{ >> + struct tegra_i2c_dev *i2c_dev =3D 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 =3D dev_get_drvdata(dev); >> + int ret; >> + >> + ret =3D tegra_i2c_init(i2c_dev, false); >> + if (ret) >> + return ret; >=20 > We're expecting that tegra_i2c_init returns a error code on a failure > and nothing else, hence it will be a bit more expressive to name the > returned variable as "err". There is nothing wrong with yours variant, > this is just a very minor recommendation from me. Please note that a bit > more wise choice of the names makes easier to follow the code for other > people and hence results in a cleaner code. Agreed. >=20 >> + >> + i2c_mark_adapter_resumed(&i2c_dev->adapter); >=20 > Please add a blank line here for a better readability and to make the > patch consistent. You added the blank line in a similar case of > tegra_i2c_suspend() and this makes it inconsistent. >=20 OK. >> + return 0; >> +} >> + >> static const struct dev_pm_ops tegra_i2c_pm =3D { >> + SET_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume) >> SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resum= e, >> NULL) >> }; >> I shall send updated patch with suggested changes. -thanks, Bitan