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=-13.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 1144BC6369E for ; Wed, 18 Nov 2020 03:54:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A589D2220B for ; Wed, 18 Nov 2020 03:54:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="NM9+KWit" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727272AbgKRDy3 (ORCPT ); Tue, 17 Nov 2020 22:54:29 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:51256 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbgKRDy2 (ORCPT ); Tue, 17 Nov 2020 22:54:28 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1605671668; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=HgWcu5vua69Grp1B6OILlPqQacb84SME0P+FvoHbIVI=; b=NM9+KWiteH5pCyGHFfiyejkRKzuUr0pgXjFp6bcaUpQL6TbxDnw+aG0rTISahdjH2GeY+VNS MgXR3HE566w/K6bDudRs5YlYe63siW6pElYkdSajorgV0akTLX/kAdsR7y+vbKmxS64zrEj8 hleFDzDbmb9ENtmFIqjcfSJ/CvI= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyJlNmU5NiIsICJsaW51eC1zY3NpQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-west-2.postgun.com with SMTP id 5fb49af38bd2e3c2227623bf (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 18 Nov 2020 03:54:27 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 55332C43463; Wed, 18 Nov 2020 03:54:27 +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: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 7229DC433C6; Wed, 18 Nov 2020 03:54:26 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 18 Nov 2020 11:54:26 +0800 From: Can Guo To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, kernel-team@android.com, alim.akhtar@samsung.com, avri.altman@wdc.com, bvanassche@acm.org, martin.petersen@oracle.com, stanley.chu@mediatek.com, Jaegeuk Kim Subject: Re: [PATCH v5 2/7] scsi: ufs: atomic update for clkgating_enable In-Reply-To: <20201117165839.1643377-3-jaegeuk@kernel.org> References: <20201117165839.1643377-1-jaegeuk@kernel.org> <20201117165839.1643377-3-jaegeuk@kernel.org> Message-ID: X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2020-11-18 00:58, Jaegeuk Kim wrote: > From: Jaegeuk Kim > > When giving a stress test which enables/disables clkgating, we hit > device > timeout sometimes. This patch avoids subtle racy condition to address > it. > > Note that, this requires a patch to address the device stuck by > REQ_CLKS_OFF in > __ufshcd_release(). > > The fix is "scsi: ufs: avoid to call REQ_CLKS_OFF to CLKS_OFF". > > Signed-off-by: Jaegeuk Kim Reviewed-by: Can Guo > --- > drivers/scsi/ufs/ufshcd.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index cc8d5f0c3fdc..6c9269bffcbd 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -1808,19 +1808,19 @@ static ssize_t > ufshcd_clkgate_enable_store(struct device *dev, > return -EINVAL; > > value = !!value; > + > + spin_lock_irqsave(hba->host->host_lock, flags); > if (value == hba->clk_gating.is_enabled) > goto out; > > - if (value) { > - ufshcd_release(hba); > - } else { > - spin_lock_irqsave(hba->host->host_lock, flags); > + if (value) > + __ufshcd_release(hba); > + else > hba->clk_gating.active_reqs++; > - spin_unlock_irqrestore(hba->host->host_lock, flags); > - } > > hba->clk_gating.is_enabled = value; > out: > + spin_unlock_irqrestore(hba->host->host_lock, flags); > return count; > }