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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 14E4DC433E3 for ; Tue, 28 Jul 2020 08:47:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E11B820759 for ; Tue, 28 Jul 2020 08:47:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="lOSu2yCV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728156AbgG1IrT (ORCPT ); Tue, 28 Jul 2020 04:47:19 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:42965 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728176AbgG1IrT (ORCPT ); Tue, 28 Jul 2020 04:47:19 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1595926038; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=Ov/MCTEZuyfgMKbGRufVJeV9XrK0K72sSxzij8exncc=; b=lOSu2yCV0bYzmsSLUkjbZzaK4dTUwcff10zndJYQ5sxNungD2y7n00X3C89XY6/pZ3uLpIoR KHMp1ocipWpHlF1QaFkuJYGnS0dIpO7qhfjsI9GzAsL+iI6/e3BpEdDM6EJmHS9DOHp9Uaaa sjjhwPFM3HYmqjIIWuSC+boYjzs= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-west-2.postgun.com with SMTP id 5f1fe612ca57a65d47cbd086 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 28 Jul 2020 08:47:14 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id CE80BC4339C; Tue, 28 Jul 2020 08:47:14 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan) by smtp.codeaurora.org (Postfix) with ESMTPSA id 14F51C433C6; Tue, 28 Jul 2020 08:47:14 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 28 Jul 2020 14:17:14 +0530 From: Sai Prakash Ranjan To: Stephen Boyd Cc: Mathieu Poirier , Mike Leach , Suzuki K Poulose , linux-arm-msm@vger.kernel.org, coresight@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCHv2] coresight: etm4x: Fix etm4_count race by moving cpuhp callbacks to init In-Reply-To: <159592494608.1360974.13925720722764973592@swboyd.mtv.corp.google.com> References: <20200728075102.30807-1-saiprakash.ranjan@codeaurora.org> <159592494608.1360974.13925720722764973592@swboyd.mtv.corp.google.com> Message-ID: X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2020-07-28 13:59, Stephen Boyd wrote: > Quoting Sai Prakash Ranjan (2020-07-28 00:51:02) >> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c >> b/drivers/hwtracing/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 = never, 2 = >> self-hosted"); >> >> -/* 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. > Yes, will change it. >> { >> int ret; >> >> - if (etm4_count++) >> - return 0; >> - >> ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb); >> if (ret) >> - goto reduce_count; >> + return ret; >> >> ret = >> cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, >> >> "arm/coresight4:starting", >> @@ -1432,17 +1427,11 @@ static int etm4_pm_setup_cpuslocked(void) >> >> unregister_notifier: >> cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); >> - >> -reduce_count: >> - --etm4_count; >> return ret; >> } >> >> static void etm4_pm_clear(void) > > This is __init too? > Will change. >> { >> - if (--etm4_count != 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 = { >> .probe = etm4_probe, >> .id_table = etm4_ids, >> }; >> -builtin_amba_driver(etm4x_driver); >> + >> +static int __init etm4x_init(void) >> +{ >> + int ret; >> + >> + cpus_read_lock(); >> + ret = etm4_pm_setup_cpuslocked(); >> + cpus_read_unlock(); >> + >> + /* etm4_pm_setup_cpuslocked() does its own cleanup - exit on >> error */ >> + if (ret) >> + return ret; >> + >> + ret = amba_driver_register(&etm4x_driver); >> + if (ret) { >> + pr_info("Error registering etm4x driver\n"); > > Use pr_err() please. > Yes indeed, will change. >> + 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? > Will change. >> +} >> +module_init(etm4x_init); > > It was device_initcall before with builtin_amba_driver(), best to not > change that. Sure. I will wait to see if there are any more comments on this patch and then post a v3. Thanks for the review Stephen. Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation