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 9B772C433E0 for ; Tue, 29 Dec 2020 01:48:31 +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 19FD7207DE for ; Tue, 29 Dec 2020 01:48:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 19FD7207DE 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=JqSY7tv5Nq2UeQFdfz2n6At1IxyR4oDfHtPbC3htk6c=; b=jZEoyrKyEvskasoz0Nzq8A+Ze GkWpUcMAcydmNRB0oUI8TXXBwFi+gbxNM0ydXUlO5V1uwJbfG3/HWbvEDGwK4Q6bLer/Vp+1iYt7P n6sP/doNuhsogsTgK7WdcK+0InIgbDL9KeMbkOreuOV1f5dVUpgG4UemCnjkbQE5/jqFSFvRoQLE9 0Feu0iTzvxDP2uC2XBiitfuUT4qWd6tCJKoZkoDP25XXZd0Mwb3Luwh6tc8n/cYQZL4/UHrLmxxqE EA7V6NG85/GdnK8DnNp4poQUw4Rub7rYzOa0pNosTdmZ/cwNYgsMSxO5OIxu0Q2DFqPiEwq0gRjix jDbfG5Xkw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ku47W-0005TW-IE; Tue, 29 Dec 2020 01:48:18 +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 1ku47T-0005T4-PW for linux-mediatek@lists.infradead.org; Tue, 29 Dec 2020 01:48:17 +0000 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1609206493; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=g7uVnjV+Q9ur5+jW3/IYGRkZdqHPgWp3kNlcTu1ULeo=; b=Zns+197Hv8RzwfnBoJFjSz+yPDxTNtcfbqNTCGSG12LgTPbJPJQOfzOq+N2gIvRPCTsuKVbn NavLo8i3abwe4YEtUp57zc4PJzzaF3yceCzR3rGPxNjdmnnwkUMpmEYz0QcAZkO4J7U4+eXS +vzVyeCwYl5KTF2goKoqTZPvasY= 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-east-1.postgun.com with SMTP id 5fea8adcb00c0d7ad4b8ef8d (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 29 Dec 2020 01:48:12 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 61002C43464; Tue, 29 Dec 2020 01:48:11 +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 7C481C433CA; Tue, 29 Dec 2020 01:48:08 +0000 (UTC) MIME-Version: 1.0 Date: Tue, 29 Dec 2020 09:48:08 +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: <4c3035c418d0a0c4344be84fb1919314@codeaurora.org> References: <1608644981-46267-1-git-send-email-ziqichen@codeaurora.org> <4c3035c418d0a0c4344be84fb1919314@codeaurora.org> Message-ID: <182321abfc98e0cfca071d1ec1255f6d@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_204815_944590_19AA337B X-CRM114-Status: GOOD ( 31.87 ) 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 09:18, Can Guo wrote: > 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. > Besides, currently this device reset vops is only registered by ufs-qcom.c and ufs-mediatek.c, meaning any delays that we put in the common code are not necessary for those who do not have this vops registered, i.e ufs-exynos.c, ufs-hisi.c. 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