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=-8.1 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,USER_AGENT_SANE_1 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 1FFB7C33CB1 for ; Fri, 17 Jan 2020 16:28:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E616D214AF for ; Fri, 17 Jan 2020 16:28:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="e9vHwv7y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727022AbgAQQ2I (ORCPT ); Fri, 17 Jan 2020 11:28:08 -0500 Received: from mail-lj1-f195.google.com ([209.85.208.195]:36708 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726744AbgAQQ2I (ORCPT ); Fri, 17 Jan 2020 11:28:08 -0500 Received: by mail-lj1-f195.google.com with SMTP id r19so27071601ljg.3 for ; Fri, 17 Jan 2020 08:28:06 -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=DVtM7Y++Nwm669eZlqu0DoqcWAl43rRW+YNZE3sPUP8=; b=e9vHwv7ybLgbij5g6Q2KcM7YsfQ059X6BS9icm/fu8nBElEcJe+yzuu6tQkY7qHm3F 1IlihmFQkNcL+l13D2z3wH1DrDe+z7yhzxhdhfhTG1x9mJAmP4NXMwsQT9+tQX+ppv5H rDvIDbsbHydaOi06Vuia/AwP6GFPw4509i6oo35ik/u6zK88GqrjPAjXPvZfSFDXXM0R UD6UD70Q5u5P2TZOCF/pI1hoBkxDZapmEp0UqOkoh5Arevbn8ZJLiFH/e8oOTGhs4RpD QUNWnGvX6VnzKrLdN/VBx1wp7IdHQ0pXhPJmY0HK40wBcXqNyg2BHAmLNgsa9DjK8Z90 DjSg== 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=DVtM7Y++Nwm669eZlqu0DoqcWAl43rRW+YNZE3sPUP8=; b=HHjTagTnN8YmSfnB/J3HOmsU27J64aMvnlBhUPrw/mWULXQq8P6pZTNdIO3iepE6Vq LadlKh1GRYdgENuBBFSOgxGsxetR9YE0voXDsxNDfUJHMcitKxHxhXz0hzw20Rz0kHHU HssBCYhoyw9YwGf3mEh1QlxzlcOvXrwtPutJ75nYU8JK8wTMGnAC+2WRQIHqy2UErOO1 a2udZQSaOnXl/ZI+svkWj2kfGUlYgJgV6aua/FYlvTshbl7Zk/G94vD9hRSPXvpj+Owe 1YGWG6f2nSCqLFqiVMxWqZKeb3k9svHmXEnRv5FC7z/61pi6MCnd99HHC2GL6aK/jVKm JJ4A== X-Gm-Message-State: APjAAAXgO148JWx/QiTriTAYDt2yPPwXrAtiUAhj48FWZ0uGg9xBol8I ZBURbB4nTYRLwefWWrwyNVQ= X-Google-Smtp-Source: APXvYqyp5l6M071WDmx3fmtCoaBi+oH599+XsaULfk5uqgFdDmoff+Y1TDg5kshBK7FDMsdiieRdFQ== X-Received: by 2002:a2e:880a:: with SMTP id x10mr6067949ljh.211.1579278486215; Fri, 17 Jan 2020 08:28:06 -0800 (PST) Received: from [192.168.2.145] (79-139-233-37.dynamic.spd-mgts.ru. [79.139.233.37]) by smtp.googlemail.com with ESMTPSA id g15sm12459368ljn.32.2020.01.17.08.28.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 17 Jan 2020 08:28:05 -0800 (PST) Subject: Re: [PATCH] regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage To: Enric Balletbo i Serra , linux-kernel@vger.kernel.org, Mark Brown Cc: Collabora Kernel ML , drinkcat@chromium.org, dianders@chromium.org, Liam Girdwood , mka@chromium.org References: <20200116094543.2847321-1-enric.balletbo@collabora.com> From: Dmitry Osipenko Message-ID: <1fdaed3c-05e0-4756-5013-5cc59a766e2f@gmail.com> Date: Fri, 17 Jan 2020 19:28:04 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: <20200116094543.2847321-1-enric.balletbo@collabora.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 16.01.2020 12:45, Enric Balletbo i Serra пишет: > `cat /sys/kernel/debug/regulator/regulator_summary` ends on a deadlock > when you have a voltage controlled regulator (vctrl). > > The problem is that the vctrl_get_voltage() and vctrl_set_voltage() calls the > regulator_get_voltage() and regulator_set_voltage() and that will try to lock > again the dependent regulators (the regulator supplying the control voltage). > > Fix the issue by exporting the unlocked version of the regulator_get_voltage() > and regulator_set_voltage() API so drivers that need it, like the voltage > controlled regulator driver can use it. > > Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") > Reported-by: Douglas Anderson > Signed-off-by: Enric Balletbo i Serra > --- > > drivers/regulator/core.c | 2 ++ > drivers/regulator/vctrl-regulator.c | 38 +++++++++++++++++------------ > 2 files changed, 25 insertions(+), 15 deletions(-) > > diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c > index 03d79fee2987..e7d167ce326c 100644 > --- a/drivers/regulator/core.c > +++ b/drivers/regulator/core.c > @@ -3470,6 +3470,7 @@ int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV, > out: > return ret; > } > +EXPORT_SYMBOL(regulator_set_voltage_rdev); > > static int regulator_limit_voltage_step(struct regulator_dev *rdev, > int *current_uV, int *min_uV) > @@ -4034,6 +4035,7 @@ int regulator_get_voltage_rdev(struct regulator_dev *rdev) > return ret; > return ret - rdev->constraints->uV_offset; > } > +EXPORT_SYMBOL(regulator_get_voltage_rdev); I think it should be EXPORT_SYMBOL_GPL().