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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 61294C433E5 for ; Tue, 28 Jul 2020 08:29:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D0D720809 for ; Tue, 28 Jul 2020 08:29:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="ejEGGvg9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728195AbgG1I3K (ORCPT ); Tue, 28 Jul 2020 04:29:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728042AbgG1I3J (ORCPT ); Tue, 28 Jul 2020 04:29:09 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14729C061794 for ; Tue, 28 Jul 2020 01:29:09 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id e8so11447845pgc.5 for ; Tue, 28 Jul 2020 01:29:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:content-transfer-encoding:in-reply-to:references :subject:from:cc:to:date:message-id:user-agent; bh=yZsNfus+6QxB/2Q1/ypFJuiPTGp9cOvML6i0dLAUdac=; b=ejEGGvg9afWN+1y9f+oMsCwu34xhvRkvayj6gOjnrHe4jy2EJmceBZ2vFQgag+khsr 7ca5BnlFiO+UHKZ0RNKBKkA1WHQpIHiOKR/m0ToBWXQYAxkklg2OlXj3fMIQVtqKE3lD JI++O+B2lfF/GMviF5c2JM+7LUjRI2SElFT/w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:content-transfer-encoding :in-reply-to:references:subject:from:cc:to:date:message-id :user-agent; bh=yZsNfus+6QxB/2Q1/ypFJuiPTGp9cOvML6i0dLAUdac=; b=IaS7pZAACGlpsesqvw3fuA49xSkdcUEbEdVG6P9elsWss64VzWbfMag9gCaJspak00 tu4PAR8y25HOqUfE+EVpUS00JymTOXm5nJxAe/kUkwle0PZfNm9B2Crw5Gt/JKoLtFlf PBGJacaxdRnvO+rjaWE5AghK2ZhYSiRZ9GdnUQ+k1Kq562JuxV1IOooVIPP/3SlqSG1l eeMrW53kJQyGdDpvxi/REKkbf5sMb8zEH8GyInWJIP7Ehb4ju4vdbuaq6b2vQ3uMqu0m AOAfNVcYu7/06h+WxCmli99+N6LJSOeIcQWh5u247AVA/JEbZdUjwYCI1EkY78zDC2CL ZloQ== X-Gm-Message-State: AOAM530DGabsg3y/84GUKXxgV5+JXnBjTnfcWGbHys1fa9sqHw1p/sgF ikrSv5WxF7usQfr+9WOrqIpBk86g6dc= X-Google-Smtp-Source: ABdhPJyW9jUuaOyVc/e8KZvS6QCn6ltABXxe0vW3hPZVBAQOy7+lfoVizNyt8xrxJoHZ7VqHTpvdsg== X-Received: by 2002:aa7:91cd:: with SMTP id z13mr24700924pfa.133.1595924948476; Tue, 28 Jul 2020 01:29:08 -0700 (PDT) Received: from chromium.org ([2620:15c:202:1:3e52:82ff:fe6c:83ab]) by smtp.gmail.com with ESMTPSA id v28sm18481742pgn.81.2020.07.28.01.29.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jul 2020 01:29:07 -0700 (PDT) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20200728075102.30807-1-saiprakash.ranjan@codeaurora.org> References: <20200728075102.30807-1-saiprakash.ranjan@codeaurora.org> Subject: Re: [PATCHv2] coresight: etm4x: Fix etm4_count race by moving cpuhp callbacks to init From: Stephen Boyd Cc: Sai Prakash Ranjan , linux-arm-msm@vger.kernel.org, coresight@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: Mathieu Poirier , Mike Leach , Sai Prakash Ranjan , Suzuki K Poulose Date: Tue, 28 Jul 2020 01:29:06 -0700 Message-ID: <159592494608.1360974.13925720722764973592@swboyd.mtv.corp.google.com> User-Agent: alot/0.9.1 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Quoting Sai Prakash Ranjan (2020-07-28 00:51:02) > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtr= acing/coresight/coresight-etm4x.c > index 6d7d2169bfb2..adb71987a1e3 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x.c > @@ -48,8 +48,6 @@ module_param(pm_save_enable, int, 0444); > MODULE_PARM_DESC(pm_save_enable, > "Save/restore state on power down: 1 =3D never, 2 =3D self-hosted= "); > =20 > -/* The number of ETMv4 currently registered */ > -static int etm4_count; > static struct etmv4_drvdata *etmdrvdata[NR_CPUS]; > static void etm4_set_default_config(struct etmv4_config *config); > static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, > @@ -1403,12 +1401,9 @@ static int etm4_pm_setup_cpuslocked(void) Is this only called from __init now? If so please mark it as __init then. > { > int ret; > =20 > - if (etm4_count++) > - return 0; > - > ret =3D cpu_pm_register_notifier(&etm4_cpu_pm_nb); > if (ret) > - goto reduce_count; > + return ret; > =20 > ret =3D cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIG= HT_STARTING, > "arm/coresight4:starti= ng", > @@ -1432,17 +1427,11 @@ static int etm4_pm_setup_cpuslocked(void) > =20 > unregister_notifier: > cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); > - > -reduce_count: > - --etm4_count; > return ret; > } > =20 > static void etm4_pm_clear(void) This is __init too? > { > - if (--etm4_count !=3D 0) > - return; > - > cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); > cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); > if (hp_online) { > @@ -1598,4 +1576,29 @@ static struct amba_driver etm4x_driver =3D { > .probe =3D etm4_probe, > .id_table =3D etm4_ids, > }; > -builtin_amba_driver(etm4x_driver); > + > +static int __init etm4x_init(void) > +{ > + int ret; > + > + cpus_read_lock(); > + ret =3D etm4_pm_setup_cpuslocked(); > + cpus_read_unlock(); > + > + /* etm4_pm_setup_cpuslocked() does its own cleanup - exit on erro= r */ > + if (ret) > + return ret; > + > + ret =3D amba_driver_register(&etm4x_driver); > + if (ret) { > + pr_info("Error registering etm4x driver\n"); Use pr_err() please. > + goto err_init; > + } > + > + return ret; > + > +err_init: Why is this a goto? > + etm4_pm_clear(); > + return ret; Instead of just putting this in the if (ret) arm? > +} > +module_init(etm4x_init); It was device_initcall before with builtin_amba_driver(), best to not change that.