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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 926C5C04A68 for ; Fri, 29 Jul 2022 20:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239111AbiG2UMH (ORCPT ); Fri, 29 Jul 2022 16:12:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239023AbiG2UME (ORCPT ); Fri, 29 Jul 2022 16:12:04 -0400 Received: from mail-pf1-f176.google.com (mail-pf1-f176.google.com [209.85.210.176]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F92684EC6; Fri, 29 Jul 2022 13:12:04 -0700 (PDT) Received: by mail-pf1-f176.google.com with SMTP id k79so1320650pfd.8; Fri, 29 Jul 2022 13:12:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc; bh=WqEsTmzo4i5fSlXYqdazJ4mWkRbar+SoV/KUVTSJNWs=; b=wQHXFNyXsTJWyHy8Es7Wc+FPEkRLvliewTYhZLHZfVTDk2FCi739eXGLRNRd067+XX axXk18E4R8M8mAMwvo4WTQmA+oR2I0SLacgoOZZ5d1OMIZX/xnes5/rPW8Eln0PJB2Wt gh/zq8MGJoB6yDM4xhVpc3ya5bMW0rGU00RwyuDwCpyA3WzCZn09pvO4CrrkWzdrNapE k7cJUVUv7p2udLmvmGuHWHffI8bZLo7CLk4/4EP7CbVQa3Uydy5FxU+5CeGOyTlZ32/3 A21C8uvKlvpSX7H059f5AZzt7+4evgsXygMOcQWxve+QjHNTJ/LfPeUCdpBRZDlD3kJk El7A== X-Gm-Message-State: ACgBeo0f6ZNX6etzdunuuJq/P9ETjvLa96lFaShN3bwWWo9gy3W6fqnn rQ43DT6Z0+Q3Hmm3NhxUkjE= X-Google-Smtp-Source: AA6agR6iI8nn5Vcvd08VLRPwuWa8rIn7Kk4foThZXSwlQ5u9RHtvmZKSHYJvGz2KRhxKOklgT7jDBg== X-Received: by 2002:a63:4407:0:b0:41b:b1df:cf6e with SMTP id r7-20020a634407000000b0041bb1dfcf6emr1509227pga.605.1659125523637; Fri, 29 Jul 2022 13:12:03 -0700 (PDT) Received: from ?IPV6:2620:15c:211:201:f090:7a49:3465:6a5? ([2620:15c:211:201:f090:7a49:3465:6a5]) by smtp.gmail.com with ESMTPSA id e64-20020a621e43000000b0052ab42ea0c5sm3376910pfe.147.2022.07.29.13.12.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 29 Jul 2022 13:12:02 -0700 (PDT) Message-ID: <7e8c58cf-64c1-8426-bf22-97d3df85ed38@acm.org> Date: Fri, 29 Jul 2022 13:11:59 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v1] scsi: ufs: Fix ufshcd_scale_clks decision in recovery flow Content-Language: en-US To: Stanley Chu , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, martin.petersen@oracle.com, avri.altman@wdc.com, alim.akhtar@samsung.com, jejb@linux.ibm.com Cc: peter.wang@mediatek.com, chun-hung.wu@mediatek.com, alice.chao@mediatek.com, powen.kao@mediatek.com, mason.zhang@mediatek.com, qilin.tan@mediatek.com, lin.gui@mediatek.com, eddie.huang@mediatek.com, tun-yu.yu@mediatek.com, cc.chou@mediatek.com, chaotian.jing@mediatek.com, jiajie.hao@mediatek.com References: <20220729075519.4665-1-stanley.chu@mediatek.com> From: Bart Van Assche In-Reply-To: <20220729075519.4665-1-stanley.chu@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/29/22 00:55, Stanley Chu wrote: > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > index 581d88af07ab..dc57a7988023 100644 > --- a/drivers/ufs/core/ufshcd.c > +++ b/drivers/ufs/core/ufshcd.c > @@ -1574,8 +1574,6 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev, > ufshcd_rpm_get_sync(hba); > ufshcd_hold(hba, false); > > - hba->clk_scaling.is_enabled = value; > - > if (value) { > ufshcd_resume_clkscaling(hba); > } else { > @@ -1586,6 +1584,8 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev, > __func__, err); > } > > + hba->clk_scaling.is_enabled = value; > + > ufshcd_release(hba); > ufshcd_rpm_put_sync(hba); > out: > @@ -7259,7 +7259,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba) > hba->silence_err_logs = false; > > /* scale up clocks to max frequency before full reinitialization */ > - ufshcd_scale_clks(hba, true); > + if (ufshcd_is_clkscaling_supported(hba) && hba->clk_scaling.is_enabled) > + ufshcd_scale_clks(hba, true); > > err = ufshcd_hba_enable(hba); I see a race condition between the hba->clk_scaling.is_enabled check in ufshcd_host_reset_and_restore() and the code that sets ufshcd_clkscale_enable_store(). Shouldn't the code in ufshcd_host_reset_and_restore() that scales up the clocks be serialized against ufshcd_clkscale_enable_store()? Thanks, Bart.