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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 CA5D0C4332D for ; Mon, 8 Mar 2021 17:18:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A47316522C for ; Mon, 8 Mar 2021 17:18:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230124AbhCHRSC (ORCPT ); Mon, 8 Mar 2021 12:18:02 -0500 Received: from mail-ot1-f47.google.com ([209.85.210.47]:44394 "EHLO mail-ot1-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbhCHRRs (ORCPT ); Mon, 8 Mar 2021 12:17:48 -0500 Received: by mail-ot1-f47.google.com with SMTP id f33so9885673otf.11; Mon, 08 Mar 2021 09:17:47 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LLAuJN9s4HTUz+X3eqpXsgn6nsnEDUj7ZWPMggJ9UkQ=; b=IVQgnNgoE6v5ns7VFLQAOwO/rli2DbxArjKyxZYCHjdpSuaHYi1mWM9Ryo5Yv5/pQg 9VkqSb4o0YOwKGOm+KtEnpSmomGGJ6dWC5kw/AXt8B7kGRqmtsPmehUUv+5035U8ofyR MH9/SNAqbu3vAidAjJNOTF0JuDXcTA8h6twgvn9e5Yrp678HBoY1GPGbNzhB0ltSEt31 NNVyGwOWVIyDaQxihxLUZnCuLdkp8qPdoXt9/x8tLmK/lCNXmP26b52wgM18n/6O6RZN KYobZbAGgO3zgbEvEKZ1Fm7JOkfdnPlvtL7QVOb36P6rbum03/+N2flIsxEQJLe8y2rL ovIw== X-Gm-Message-State: AOAM530p52QLixSdHksXVgZKeIFeMKGuYra6xLG+Wm9F3rxdDC2y8G4b zYI/bKeFolrt0lJd5fbjxFO61FMbuh2nJasX4PY= X-Google-Smtp-Source: ABdhPJy3ixyulNXbgWmf58jGUR8/00MLlyH/pcH6DEyialh2MI6c5M/QGmRiA25J/arfLKcbGIBnHzQ42xcfMZe/12s= X-Received: by 2002:a05:6830:1e03:: with SMTP id s3mr10129409otr.321.1615223867208; Mon, 08 Mar 2021 09:17:47 -0800 (PST) MIME-Version: 1.0 References: <0576d6eae15486740c25767e2d8805f7e94eb79d.1614725302.git.asutoshd@codeaurora.org> <85086647-7292-b0a2-d842-290818bd2858@intel.com> <6e98724d-2e75-d1fe-188f-a7010f86c509@codeaurora.org> <20210306161616.GC74411@rowland.harvard.edu> In-Reply-To: From: "Rafael J. Wysocki" Date: Mon, 8 Mar 2021 18:17:35 +0100 Message-ID: Subject: Re: [PATCH v10 1/2] scsi: ufs: Enable power management for wlun To: "Asutosh Das (asd)" Cc: Alan Stern , "Rafael J. Wysocki" , Adrian Hunter , cang@codeaurora.org, "Martin K. Petersen" , "open list:TARGET SUBSYSTEM" , Bart Van Assche , linux-arm-msm , Alim Akhtar , Avri Altman , "James E.J. Bottomley" , Krzysztof Kozlowski , Stanley Chu , Andy Gross , Bjorn Andersson , Steven Rostedt , Ingo Molnar , Matthias Brugger , Kiwoong Kim , Bean Huo , Lee Jones , Wei Yongjun , Dinghao Liu , "Gustavo A. R. Silva" , Tomas Winkler , Jaegeuk Kim , Satya Tangirala , open list , "moderated list:ARM/SAMSUNG S3C, S5P AND EXYNOS ARM ARCHITECTURES" , "open list:ARM/SAMSUNG S3C, S5P AND EXYNOS ARM ARCHITECTURES" , "moderated list:UNIVERSAL FLASH STORAGE HOST CONTROLLER DRIVER..." , Linux-PM mailing list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 8, 2021 at 5:21 PM Rafael J. Wysocki wrote: > > On Sat, Mar 6, 2021 at 5:17 PM Alan Stern wrote: > > > > On Fri, Mar 05, 2021 at 06:54:24PM -0800, Asutosh Das (asd) wrote: > > > > > Now during my testing I see a weird issue sometimes (1 in 7). > > > Scenario - bootups > > > > > > Issue: > > > The supplier 'ufs_device_wlun 0:0:0:49488' goes into runtime suspend even > > > when one/more of its consumers are in RPM_ACTIVE state. > > > > > > *Log: > > > [ 10.056379][ T206] sd 0:0:0:1: [sdb] Synchronizing SCSI cache > > > [ 10.062497][ T113] sd 0:0:0:5: [sdf] Synchronizing SCSI cache > > > [ 10.356600][ T32] sd 0:0:0:7: [sdh] Synchronizing SCSI cache > > > [ 10.362944][ T174] sd 0:0:0:3: [sdd] Synchronizing SCSI cache > > > [ 10.696627][ T83] sd 0:0:0:2: [sdc] Synchronizing SCSI cache > > > [ 10.704562][ T170] sd 0:0:0:6: [sdg] Synchronizing SCSI cache > > > [ 10.980602][ T5] sd 0:0:0:0: [sda] Synchronizing SCSI cache > > > > > > /** Printing all the consumer nodes of supplier **/ > > > [ 10.987327][ T5] ufs_device_wlun 0:0:0:49488: usage-count @ suspend: 0 > > > <-- this is the usage_count > > > [ 10.994440][ T5] ufs_rpmb_wlun 0:0:0:49476: PM state - 2 > > > [ 11.000402][ T5] scsi 0:0:0:49456: PM state - 2 > > > [ 11.005453][ T5] sd 0:0:0:0: PM state - 2 > > > [ 11.009958][ T5] sd 0:0:0:1: PM state - 2 > > > [ 11.014469][ T5] sd 0:0:0:2: PM state - 2 > > > [ 11.019072][ T5] sd 0:0:0:3: PM state - 2 > > > [ 11.023595][ T5] sd 0:0:0:4: PM state - 0 << RPM_ACTIVE > > > [ 11.353298][ T5] sd 0:0:0:5: PM state - 2 > > > [ 11.357726][ T5] sd 0:0:0:6: PM state - 2 > > > [ 11.362155][ T5] sd 0:0:0:7: PM state - 2 > > > [ 11.366584][ T5] ufshcd-qcom 1d84000.ufshc: __ufshcd_wl_suspend - 8709 > > > [ 11.374366][ T5] ufs_device_wlun 0:0:0:49488: __ufshcd_wl_suspend - > > > (0) has rpm_active flags > > Do you mean that rpm_active of the link between the consumer and the > supplier is greater than 0 at this point and the consumer is I mean is rpm_active of the link greater than 1 (because 1 means "no active references to the supplier")? > RPM_ACTIVE, but the supplier suspends successfully nevertheless? > > > > [ 11.383376][ T5] ufs_device_wlun 0:0:0:49488: > > > ufshcd_wl_runtime_suspend <-- Supplier suspends fine. > > > [ 12.977318][ T174] sd 0:0:0:4: [sde] Synchronizing SCSI cache > > > > > > And the the suspend of sde is stuck now: > > > schedule+0x9c/0xe0 > > > schedule_timeout+0x40/0x128 > > > io_schedule_timeout+0x44/0x68 > > > wait_for_common_io+0x7c/0x100 > > > wait_for_completion_io+0x14/0x20 > > > blk_execute_rq+0x90/0xcc > > > __scsi_execute+0x104/0x1c4 > > > sd_sync_cache+0xf8/0x2a0 > > > sd_suspend_common+0x74/0x11c > > > sd_suspend_runtime+0x14/0x20 > > > scsi_runtime_suspend+0x64/0x94 > > > __rpm_callback+0x80/0x2a4 > > > rpm_suspend+0x308/0x614 > > > pm_runtime_work+0x98/0xa8 > > > > > > I added 'DL_FLAG_RPM_ACTIVE' while creating links. > > > if (hba->sdev_ufs_device) { > > > link = device_link_add(&sdev->sdev_gendev, > > > &hba->sdev_ufs_device->sdev_gendev, > > > DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE); > > > I didn't expect this to resolve the issue anyway and it didn't. > > > > > > Another interesting point here is when I resume any of the above suspended > > > consumers, it all goes back to normal, which is kind of expected. I tried > > > resuming the consumer and the supplier is resumed and the supplier is > > > suspended when all the consumers are suspended. > > > > > > Any pointers on this issue please? > > > > > > @Bart/@Alan - Do you've any pointers please? > > > > It's very noticeable that although you seem to have isolated a bug in > > the power management subsystem (supplier goes into runtime suspend > > even when one of its consumers is still active), you did not CC the > > power management maintainer or mailing list. > > > > I have added the appropriate CC's. > > Thanks Alan!