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=-13.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 39B25C433E0 for ; Tue, 29 Dec 2020 01:18:38 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D54B7216C4 for ; Tue, 29 Dec 2020 01:18:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D54B7216C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=n6abmE9wogXD61woM8Zy46cur+BmPKIoLCnbCHWSCOg=; b=swXBHN2f7GNtdmYpcv8ik1EHn 2MChUTpnv80wWLUN0oxo20PSzppqx7nfKJCYyi86aeDAGY418xmXN6T2mgeK50k8wMWqWDyQkiM4J bmHZLwKakP+RMm26QxETxnp/uv9T9oqALxJFvjbxPjY36qc1x4ROjh2dHOroeQDDYOfFm2jG84/X3 id0LPG95FS2EIcgje1TDFkwAn0k5iW8SV0kYGjkWs+fFWLTmwtdA3giMvtAiyYEs7IBQIqD1zbhn1 2WxbOSMObTuZ3MM6hDnLoS3uYvzBakNa+PQCQC7BFZ9X25CwZkURoHhyh3awtfbXmClPFZqP6FyxG xIPwDnmcQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ku3eb-0002dT-Rx; Tue, 29 Dec 2020 01:18:25 +0000 Received: from m43-15.mailgun.net ([69.72.43.15]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ku3eY-0002ce-NG for linux-mediatek@lists.infradead.org; Tue, 29 Dec 2020 01:18:24 +0000 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1609204695; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=3b/eqLh0MsIttZBtQ8VRVS9f7hdj+1u+h/hKaGzqkkA=; b=T2U9NUlWqnMeJ0LYRRBNy+rv5lPDng72w/CjvM1umsz72VjndntEP3cT56lwuO7crrO3Enw8 XqeLUPyOxo+MuYSoud2xD8KCRfMdQclInM18p7VgNuk2ZCMLQzyipQIH4BmV+YqyibUgBo19 OSWqSOOuPocT+dzoySj0Lzb8Gkc= X-Mailgun-Sending-Ip: 69.72.43.15 X-Mailgun-Sid: WyI0ZDIyMyIsICJsaW51eC1tZWRpYXRla0BsaXN0cy5pbmZyYWRlYWQub3JnIiwgImJlOWU0YSJd 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 5fea83d66d011aad66978913 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 29 Dec 2020 01:18:14 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id A006AC43469; Tue, 29 Dec 2020 01:18:14 +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: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 61DA2C433C6; Tue, 29 Dec 2020 01:18:11 +0000 (UTC) MIME-Version: 1.0 Date: Tue, 29 Dec 2020 09:18:11 +0800 From: Can Guo To: Bjorn Andersson Subject: Re: [PATCH RFC v4 1/1] scsi: ufs: Fix ufs power down/on specs violation In-Reply-To: References: <1608644981-46267-1-git-send-email-ziqichen@codeaurora.org> Message-ID: <4c3035c418d0a0c4344be84fb1919314@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201228_201823_014399_5AC0D8EC X-CRM114-Status: GOOD ( 34.94 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nguyenb@codeaurora.org, Alim Akhtar , kwmad.kim@samsung.com, Bean Huo , Satya Tangirala , vinholikatti@gmail.com, jejb@linux.vnet.ibm.com, Bart Van Assche , linux-scsi@vger.kernel.org, Ziqi Chen , Andy Gross , kernel-team@android.com, salyzyn@google.com, "open list:ARM/QUALCOMM SUPPORT" , "James E.J. Bottomley" , Avri Altman , "moderated list:UNIVERSAL FLASH STORAGE HOST CONTROLLER DRIVER..." , Matthias Brugger , stanley.chu@mediatek.com, "moderated list:ARM/Mediatek SoC support" , rnayak@codeaurora.org, saravanak@google.com, martin.petersen@oracle.com, Adrian Hunter , open list , hongwus@codeaurora.org, asutoshd@codeaurora.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On 2020-12-29 01:55, Bjorn Andersson wrote: > On Tue 22 Dec 07:49 CST 2020, Ziqi Chen wrote: > >> As per specs, e.g, JESD220E chapter 7.2, while powering >> off/on the ufs device, RST_N signal and REF_CLK signal >> should be between VSS(Ground) and VCCQ/VCCQ2. >> >> To flexibly control device reset line, refactor the function >> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_ >> vops_device_reset(sturct ufs_hba *hba, bool asserted). The >> new parameter "bool asserted" is used to separate device reset >> line pulling down from pulling up. >> >> Cc: Kiwoong Kim >> Cc: Stanley Chu >> Signed-off-by: Ziqi Chen >> --- >> drivers/scsi/ufs/ufs-mediatek.c | 32 ++++++++++++++++---------------- >> drivers/scsi/ufs/ufs-qcom.c | 24 +++++++++++++++--------- >> drivers/scsi/ufs/ufshcd.c | 36 >> +++++++++++++++++++++++++----------- >> drivers/scsi/ufs/ufshcd.h | 8 ++++---- >> 4 files changed, 60 insertions(+), 40 deletions(-) >> >> diff --git a/drivers/scsi/ufs/ufs-mediatek.c >> b/drivers/scsi/ufs/ufs-mediatek.c >> index 80618af..072f4db 100644 >> --- a/drivers/scsi/ufs/ufs-mediatek.c >> +++ b/drivers/scsi/ufs/ufs-mediatek.c >> @@ -841,27 +841,27 @@ static int ufs_mtk_link_startup_notify(struct >> ufs_hba *hba, >> return ret; >> } >> >> -static int ufs_mtk_device_reset(struct ufs_hba *hba) >> +static int ufs_mtk_device_reset(struct ufs_hba *hba, bool asserted) >> { >> struct arm_smccc_res res; >> >> - ufs_mtk_device_reset_ctrl(0, res); >> + if (asserted) { >> + ufs_mtk_device_reset_ctrl(0, res); >> >> - /* >> - * The reset signal is active low. UFS devices shall detect >> - * more than or equal to 1us of positive or negative RST_n >> - * pulse width. >> - * >> - * To be on safe side, keep the reset low for at least 10us. >> - */ >> - usleep_range(10, 15); >> - >> - ufs_mtk_device_reset_ctrl(1, res); >> - >> - /* Some devices may need time to respond to rst_n */ >> - usleep_range(10000, 15000); >> + /* >> + * The reset signal is active low. UFS devices shall detect >> + * more than or equal to 1us of positive or negative RST_n >> + * pulse width. >> + * >> + * To be on safe side, keep the reset low for at least 10us. >> + */ >> + usleep_range(10, 15); > > I see no point in allowing vendors to "tweak" the 1us->10us adjustment. > The specification says 1us and we all agree that 10us gives us good > enough slack. I.e. this is common code. Hi Bjron, We tried, but Samsung fellows wanted 5us. We couldn't get a agreement on this delay in short term, so we chose to leave it in vops. > >> + } else { >> + ufs_mtk_device_reset_ctrl(1, res); >> >> - dev_info(hba->dev, "device reset done\n"); >> + /* Some devices may need time to respond to rst_n */ >> + usleep_range(10000, 15000); > > The comment in both the Qualcomm and Mediatek drivers claim that this > is > sleep relates to the UFS device (not host), so why should it be > different? > > What happens if I take the device that Mediatek see a need for a 10ms > delay and hook that up to a Qualcomm host? This really should go in the > common code. > Agree, but Qualcomm host didn't have any problems with 10us yet, so if we put the 10ms delay to common code, Qualcomm host would suffer longer delay when device reset happens - both bootup and resume(xpm_lvl = 5/6) latency would be increased. Regards, Can Guo. > > > As such I really would prefer to see these delays in the common code! > You really shouldn't write code based on a speculation that one day > there might come someone who need other values - when that day come we > can just change the code, and if it never comes we're better off with > the cleaner implementation. > > Regards, > Bjorn > >> + } >> >> return 0; >> } >> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c >> index 2206b1e..fed10e5 100644 >> --- a/drivers/scsi/ufs/ufs-qcom.c >> +++ b/drivers/scsi/ufs/ufs-qcom.c >> @@ -1406,10 +1406,11 @@ static void ufs_qcom_dump_dbg_regs(struct >> ufs_hba *hba) >> /** >> * ufs_qcom_device_reset() - toggle the (optional) device reset line >> * @hba: per-adapter instance >> + * @asserted: assert or deassert device reset line >> * >> * Toggles the (optional) reset line to reset the attached device. >> */ >> -static int ufs_qcom_device_reset(struct ufs_hba *hba) >> +static int ufs_qcom_device_reset(struct ufs_hba *hba, bool asserted) >> { >> struct ufs_qcom_host *host = ufshcd_get_variant(hba); >> >> @@ -1417,15 +1418,20 @@ static int ufs_qcom_device_reset(struct >> ufs_hba *hba) >> if (!host->device_reset) >> return -EOPNOTSUPP; >> >> - /* >> - * The UFS device shall detect reset pulses of 1us, sleep for 10us >> to >> - * be on the safe side. >> - */ >> - gpiod_set_value_cansleep(host->device_reset, 1); >> - usleep_range(10, 15); >> + if (asserted) { >> + gpiod_set_value_cansleep(host->device_reset, 1); >> >> - gpiod_set_value_cansleep(host->device_reset, 0); >> - usleep_range(10, 15); >> + /* >> + * The UFS device shall detect reset pulses of 1us, sleep for 10us >> to >> + * be on the safe side. >> + */ >> + usleep_range(10, 15); >> + } else { >> + gpiod_set_value_cansleep(host->device_reset, 0); >> + >> + /* Some devices may need time to respond to rst_n */ >> + usleep_range(10, 15); >> + } >> >> return 0; >> } >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index e221add..f2daac2 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -585,7 +585,13 @@ static void ufshcd_device_reset(struct ufs_hba >> *hba) >> { >> int err; >> >> - err = ufshcd_vops_device_reset(hba); >> + err = ufshcd_vops_device_reset(hba, true); >> + if (err) { >> + dev_err(hba->dev, "asserting device reset failed: %d\n", err); >> + return; >> + } >> + >> + err = ufshcd_vops_device_reset(hba, false); >> >> if (!err) { >> ufshcd_set_ufs_dev_active(hba); >> @@ -593,7 +599,11 @@ static void ufshcd_device_reset(struct ufs_hba >> *hba) >> hba->wb_enabled = false; >> hba->wb_buf_flush_enabled = false; >> } >> + dev_dbg(hba->dev, "device reset done\n"); >> + } else { >> + dev_err(hba->dev, "deasserting device reset failed: %d\n", err); >> } >> + >> if (err != -EOPNOTSUPP) >> ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err); >> } >> @@ -8686,8 +8696,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> if (ret) >> goto set_dev_active; >> >> - ufshcd_vreg_set_lpm(hba); >> - >> disable_clks: >> /* >> * Call vendor specific suspend callback. As these callbacks may >> access >> @@ -8703,6 +8711,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> */ >> ufshcd_disable_irq(hba); >> >> + if (ufshcd_is_link_off(hba)) >> + ufshcd_vops_device_reset(hba, true); >> + >> ufshcd_setup_clocks(hba, false); >> >> if (ufshcd_is_clkgating_allowed(hba)) { >> @@ -8711,6 +8722,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> hba->clk_gating.state); >> } >> >> + ufshcd_vreg_set_lpm(hba); >> + >> /* Put the host controller in low power mode if possible */ >> ufshcd_hba_vreg_set_lpm(hba); >> goto out; >> @@ -8778,18 +8791,19 @@ static int ufshcd_resume(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> old_link_state = hba->uic_link_state; >> >> ufshcd_hba_vreg_set_hpm(hba); >> + >> + ret = ufshcd_vreg_set_hpm(hba); >> + if (ret) >> + goto out; >> + >> /* Make sure clocks are enabled before accessing controller */ >> ret = ufshcd_setup_clocks(hba, true); >> if (ret) >> - goto out; >> + goto disable_vreg; >> >> /* enable the host irq as host controller would be active soon */ >> ufshcd_enable_irq(hba); >> >> - ret = ufshcd_vreg_set_hpm(hba); >> - if (ret) >> - goto disable_irq_and_vops_clks; >> - >> /* >> * Call vendor specific resume callback. As these callbacks may >> access >> * vendor specific host controller register space call them when the >> @@ -8797,7 +8811,7 @@ static int ufshcd_resume(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> */ >> ret = ufshcd_vops_resume(hba, pm_op); >> if (ret) >> - goto disable_vreg; >> + goto disable_irq_and_vops_clks; >> >> /* For DeepSleep, the only supported option is to have the link off >> */ >> WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && >> !ufshcd_is_link_off(hba)); >> @@ -8864,8 +8878,6 @@ static int ufshcd_resume(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> ufshcd_link_state_transition(hba, old_link_state, 0); >> vendor_suspend: >> ufshcd_vops_suspend(hba, pm_op); >> -disable_vreg: >> - ufshcd_vreg_set_lpm(hba); >> disable_irq_and_vops_clks: >> ufshcd_disable_irq(hba); >> if (hba->clk_scaling.is_allowed) >> @@ -8876,6 +8888,8 @@ static int ufshcd_resume(struct ufs_hba *hba, >> enum ufs_pm_op pm_op) >> trace_ufshcd_clk_gating(dev_name(hba->dev), >> hba->clk_gating.state); >> } >> +disable_vreg: >> + ufshcd_vreg_set_lpm(hba); >> out: >> hba->pm_op_in_progress = 0; >> if (ret) >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h >> index 9bb5f0e..d5fbaba 100644 >> --- a/drivers/scsi/ufs/ufshcd.h >> +++ b/drivers/scsi/ufs/ufshcd.h >> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info { >> * @resume: called during host controller PM callback >> * @dbg_register_dump: used to dump controller debug information >> * @phy_initialization: used to initialize phys >> - * @device_reset: called to issue a reset pulse on the UFS device >> + * @device_reset: called to assert or deassert device reset line >> * @program_key: program or evict an inline encryption key >> * @event_notify: called to notify important events >> */ >> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops { >> int (*resume)(struct ufs_hba *, enum ufs_pm_op); >> void (*dbg_register_dump)(struct ufs_hba *hba); >> int (*phy_initialization)(struct ufs_hba *); >> - int (*device_reset)(struct ufs_hba *hba); >> + int (*device_reset)(struct ufs_hba *hba, bool asserted); >> void (*config_scaling_param)(struct ufs_hba *hba, >> struct devfreq_dev_profile *profile, >> void *data); >> @@ -1216,10 +1216,10 @@ static inline void >> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba) >> hba->vops->dbg_register_dump(hba); >> } >> >> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba) >> +static inline int ufshcd_vops_device_reset(struct ufs_hba *hba, bool >> asserted) >> { >> if (hba->vops && hba->vops->device_reset) >> - return hba->vops->device_reset(hba); >> + return hba->vops->device_reset(hba, asserted); >> >> return -EOPNOTSUPP; >> } >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> Forum, >> a Linux Foundation Collaborative Project >> _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek