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[23.128.96.18]) by mx.google.com with ESMTP id j26si11614631eds.457.2020.12.21.22.14.29; Mon, 21 Dec 2020 22:14:52 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@mg.codeaurora.org header.s=smtp header.b=ghEr6ZHW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726030AbgLVGNi (ORCPT + 99 others); Tue, 22 Dec 2020 01:13:38 -0500 Received: from so254-31.mailgun.net ([198.61.254.31]:44418 "EHLO so254-31.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725938AbgLVGNi (ORCPT ); Tue, 22 Dec 2020 01:13:38 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1608617599; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=bTzOEAjYYkkK45qiQFIpzidx0Vu7oEn/P14qlsljJoE=; b=ghEr6ZHWIvW0Xs1ittDnScPaXFfQx7kpx3bjtmgyV4UYHAlKTYFFR8DjJBmujdNE1f/QRJqG eXF4WyBbvE0ESCsgcXNIqMrQRDrZC6sInF3nkI6f+DmmB4cfUe5O/98KJKcMOOUH2s0hntKp qbrwBbZ73c3Lh+CrkvV/dMSdCgg= X-Mailgun-Sending-Ip: 198.61.254.31 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-west-2.postgun.com with SMTP id 5fe18e636d011aad6617394d (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 22 Dec 2020 06:12:51 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 0665AC433CA; Tue, 22 Dec 2020 06:12:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 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 3E7C1C433C6; Tue, 22 Dec 2020 06:12:49 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 22 Dec 2020 14:12:49 +0800 From: Can Guo To: Stanley Chu Cc: Bean Huo , alim.akhtar@samsung.com, avri.altman@wdc.com, asutoshd@codeaurora.org, jejb@linux.ibm.com, martin.petersen@oracle.com, beanhuo@micron.com, bvanassche@acm.org, tomas.winkler@intel.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/7] scsi: ufs: Add "wb_on" sysfs node to control WB on/off In-Reply-To: <1608617307.14045.3.camel@mtkswgap22> References: <20201215230519.15158-1-huobean@gmail.com> <20201215230519.15158-2-huobean@gmail.com> <1608617307.14045.3.camel@mtkswgap22> Message-ID: X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-12-22 14:08, Stanley Chu wrote: > Hi Bean, > > On Wed, 2020-12-16 at 00:05 +0100, Bean Huo wrote: >> From: Bean Huo >> >> Currently UFS WriteBooster driver uses clock scaling up/down to set >> WB on/off, for the platform which doesn't support >> UFSHCD_CAP_CLK_SCALING, >> WB will be always on. Provide a sysfs attribute to enable/disable WB >> during runtime. Write 1/0 to "wb_on" sysfs node to enable/disable UFS >> WB. >> >> Reviewed-by: Avri Altman >> Reviewed-by: Stanley Chu >> Signed-off-by: Bean Huo >> --- >> drivers/scsi/ufs/ufs-sysfs.c | 41 >> ++++++++++++++++++++++++++++++++++++ >> drivers/scsi/ufs/ufshcd.c | 3 +-- >> drivers/scsi/ufs/ufshcd.h | 2 ++ >> 3 files changed, 44 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/scsi/ufs/ufs-sysfs.c >> b/drivers/scsi/ufs/ufs-sysfs.c >> index 08e72b7eef6a..f3ca3d6b82c4 100644 >> --- a/drivers/scsi/ufs/ufs-sysfs.c >> +++ b/drivers/scsi/ufs/ufs-sysfs.c >> @@ -189,6 +189,45 @@ static ssize_t auto_hibern8_store(struct device >> *dev, >> return count; >> } >> >> +static ssize_t wb_on_show(struct device *dev, struct device_attribute >> *attr, >> + char *buf) >> +{ >> + struct ufs_hba *hba = dev_get_drvdata(dev); >> + >> + return sysfs_emit(buf, "%d\n", hba->wb_enabled); >> +} >> + >> +static ssize_t wb_on_store(struct device *dev, struct >> device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + struct ufs_hba *hba = dev_get_drvdata(dev); >> + unsigned int wb_enable; >> + ssize_t res; >> + >> + if (ufshcd_is_clkscaling_supported(hba)) { >> + /* >> + * If the platform supports UFSHCD_CAP_CLK_SCALING, turn WB >> + * on/off will be done while clock scaling up/down. >> + */ >> + dev_warn(dev, "To control WB through wb_on is not allowed!\n"); >> + return -EOPNOTSUPP; >> + } >> + if (!ufshcd_is_wb_allowed(hba)) >> + return -EOPNOTSUPP; >> + >> + if (kstrtouint(buf, 0, &wb_enable)) >> + return -EINVAL; >> + >> + if (wb_enable != 0 && wb_enable != 1) >> + return -EINVAL; >> + >> + pm_runtime_get_sync(hba->dev); >> + res = ufshcd_wb_ctrl(hba, wb_enable); > > May this operation race with UFS shutdown flow? > > To be more clear, ufshcd_wb_ctrl() here may be executed after host > clock > is disabled by shutdown flow? > > If yes, we need to avoid it. I have the same doubt - can user still access sysfs nodes after system starts to run shutdown routines? If yes, then we need to remove all UFS sysfs nodes in ufshcd_shutdown(). Thanks, Can Guo. > > Thanks, > Stanley Chu > >> + pm_runtime_put_sync(hba->dev); >> + >> + return res < 0 ? res : count; >> +} >> + >> static DEVICE_ATTR_RW(rpm_lvl); >> static DEVICE_ATTR_RO(rpm_target_dev_state); >> static DEVICE_ATTR_RO(rpm_target_link_state); >> @@ -196,6 +235,7 @@ static DEVICE_ATTR_RW(spm_lvl); >> static DEVICE_ATTR_RO(spm_target_dev_state); >> static DEVICE_ATTR_RO(spm_target_link_state); >> static DEVICE_ATTR_RW(auto_hibern8); >> +static DEVICE_ATTR_RW(wb_on); >> >> static struct attribute *ufs_sysfs_ufshcd_attrs[] = { >> &dev_attr_rpm_lvl.attr, >> @@ -205,6 +245,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] >> = { >> &dev_attr_spm_target_dev_state.attr, >> &dev_attr_spm_target_link_state.attr, >> &dev_attr_auto_hibern8.attr, >> + &dev_attr_wb_on.attr, >> NULL >> }; >> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index e221add25a7e..5e1dcf4de67e 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -246,7 +246,6 @@ static inline int ufshcd_config_vreg_hpm(struct >> ufs_hba *hba, >> static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag); >> static int ufshcd_wb_buf_flush_enable(struct ufs_hba *hba); >> static int ufshcd_wb_buf_flush_disable(struct ufs_hba *hba); >> -static int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable); >> static int ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool >> set); >> static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool >> enable); >> static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba); >> @@ -5351,7 +5350,7 @@ static void >> ufshcd_bkops_exception_event_handler(struct ufs_hba *hba) >> __func__, err); >> } >> >> -static int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable) >> +int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable) >> { >> int ret; >> u8 index; >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h >> index 9bb5f0ed4124..2a97006a2c93 100644 >> --- a/drivers/scsi/ufs/ufshcd.h >> +++ b/drivers/scsi/ufs/ufshcd.h >> @@ -1068,6 +1068,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba >> *hba, >> u8 *desc_buff, int *buff_len, >> enum query_opcode desc_op); >> >> +int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable); >> + >> /* Wrapper functions for safely calling variant operations */ >> static inline const char *ufshcd_get_var_name(struct ufs_hba *hba) >> {