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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CE2D7C4724C for ; Fri, 1 May 2020 01:50:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF1AE20873 for ; Fri, 1 May 2020 01:50:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728051AbgEABuJ (ORCPT ); Thu, 30 Apr 2020 21:50:09 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:37509 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727114AbgEABuI (ORCPT ); Thu, 30 Apr 2020 21:50:08 -0400 Received: by mail-pg1-f194.google.com with SMTP id r4so3915711pgg.4; Thu, 30 Apr 2020 18:50:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=qkIeoMHtgOsTJkY1aDcu+fBY2Ht3cDIXeezTTJRV748=; b=QqGCXmjbW+PYtlg11P9wKIWUwHk0uNxTHOP1L0zwN87Jb6fsch4miK4RlJ9po258AY tc7ZUPOyxqUFPwp0Kffxs+GHERahlyQllqxy55/+QTRiuMfxg8UnR5S+Pc6IlAz1cPAi jZWlPG3+OaECOPmf6WBpQUam2l8zLQvLKt2KV+ZrlnB4NNQATIARnhLjCoFwLaom4aFB 9wRF1ojb7CWE9J8Db2UEiJ/I9eujtK1INHKcfoZDXi9bR8veOITMwX69+qRCBYx69VJR ftKB4o005UQFhNhruZri+AtWmUKtzWT60D9lTUIdki/PWN6XU4PQcAUci5GZyxkL4M26 Zccw== X-Gm-Message-State: AGi0PuaDbC26VMuzb5dFicCOsUzvpwgocPKdyTbPTFjzr9+nmqbULJA4 no3SpL1XYiteIMo44bfFzYOAOWA/N3s= X-Google-Smtp-Source: APiQypLEgLff28ZP2x8zYd3YtoDlBcERGP54sgg8E6/dfD6WzPsDz+pvqx9X0aPESAV+eI5E/lgazQ== X-Received: by 2002:a63:7801:: with SMTP id t1mr1882676pgc.192.1588297805676; Thu, 30 Apr 2020 18:50:05 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:8cd3:cd23:3cea:980a? ([2601:647:4000:d7:8cd3:cd23:3cea:980a]) by smtp.gmail.com with ESMTPSA id l64sm816022pjb.44.2020.04.30.18.50.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Apr 2020 18:50:04 -0700 (PDT) Subject: Re: [PATCH v3 1/1] scsi: pm: Balance pm_only counter of request queue during system resume To: Can Guo Cc: asutoshd@codeaurora.org, nguyenb@codeaurora.org, hongwus@codeaurora.org, rnayak@codeaurora.org, stanley.chu@mediatek.com, alim.akhtar@samsung.com, beanhuo@micron.com, Avri.Altman@wdc.com, bjorn.andersson@linaro.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com, "James E.J. Bottomley" , "Martin K. Petersen" , open list References: <1588219805-25794-1-git-send-email-cang@codeaurora.org> <9e15123e-4315-15cd-3d23-2df6144bd376@acm.org> <1ef85ee212bee679f7b2927cbbc79cba@codeaurora.org> <1e2a2e39dbb3a0f06fe95bbfd66e1648@codeaurora.org> From: Bart Van Assche Autocrypt: addr=bvanassche@acm.org; prefer-encrypt=mutual; keydata= mQENBFSOu4oBCADcRWxVUvkkvRmmwTwIjIJvZOu6wNm+dz5AF4z0FHW2KNZL3oheO3P8UZWr LQOrCfRcK8e/sIs2Y2D3Lg/SL7qqbMehGEYcJptu6mKkywBfoYbtBkVoJ/jQsi2H0vBiiCOy fmxMHIPcYxaJdXxrOG2UO4B60Y/BzE6OrPDT44w4cZA9DH5xialliWU447Bts8TJNa3lZKS1 AvW1ZklbvJfAJJAwzDih35LxU2fcWbmhPa7EO2DCv/LM1B10GBB/oQB5kvlq4aA2PSIWkqz4 3SI5kCPSsygD6wKnbRsvNn2mIACva6VHdm62A7xel5dJRfpQjXj2snd1F/YNoNc66UUTABEB AAG0JEJhcnQgVmFuIEFzc2NoZSA8YnZhbmFzc2NoZUBhY20ub3JnPokBOQQTAQIAIwUCVI67 igIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEHFcPTXFzhAJ8QkH/1AdXblKL65M Y1Zk1bYKnkAb4a98LxCPm/pJBilvci6boefwlBDZ2NZuuYWYgyrehMB5H+q+Kq4P0IBbTqTa jTPAANn62A6jwJ0FnCn6YaM9TZQjM1F7LoDX3v+oAkaoXuq0dQ4hnxQNu792bi6QyVdZUvKc macVFVgfK9n04mL7RzjO3f+X4midKt/s+G+IPr4DGlrq+WH27eDbpUR3aYRk8EgbgGKvQFdD CEBFJi+5ZKOArmJVBSk21RHDpqyz6Vit3rjep7c1SN8s7NhVi9cjkKmMDM7KYhXkWc10lKx2 RTkFI30rkDm4U+JpdAd2+tP3tjGf9AyGGinpzE2XY1K5AQ0EVI67igEIAKiSyd0nECrgz+H5 PcFDGYQpGDMTl8MOPCKw/F3diXPuj2eql4xSbAdbUCJzk2ETif5s3twT2ER8cUTEVOaCEUY3 eOiaFgQ+nGLx4BXqqGewikPJCe+UBjFnH1m2/IFn4T9jPZkV8xlkKmDUqMK5EV9n3eQLkn5g lco+FepTtmbkSCCjd91EfThVbNYpVQ5ZjdBCXN66CKyJDMJ85HVr5rmXG/nqriTh6cv1l1Js T7AFvvPjUPknS6d+BETMhTkbGzoyS+sywEsQAgA+BMCxBH4LvUmHYhpS+W6CiZ3ZMxjO8Hgc ++w1mLeRUvda3i4/U8wDT3SWuHcB3DWlcppECLkAEQEAAYkBHwQYAQIACQUCVI67igIbDAAK CRBxXD01xc4QCZ4dB/0QrnEasxjM0PGeXK5hcZMT9Eo998alUfn5XU0RQDYdwp6/kMEXMdmT oH0F0xB3SQ8WVSXA9rrc4EBvZruWQ+5/zjVrhhfUAx12CzL4oQ9Ro2k45daYaonKTANYG22y //x8dLe2Fv1By4SKGhmzwH87uXxbTJAUxiWIi1np0z3/RDnoVyfmfbbL1DY7zf2hYXLLzsJR mSsED/1nlJ9Oq5fALdNEPgDyPUerqHxcmIub+pF0AzJoYHK5punqpqfGmqPbjxrJLPJfHVKy goMj5DlBMoYqEgpbwdUYkH6QdizJJCur4icy8GUNbisFYABeoJ91pnD4IGei3MTdvINSZI5e Message-ID: <226048f7-6ad3-a625-c2ed-d9d13e096803@acm.org> Date: Thu, 30 Apr 2020 18:50:03 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <1e2a2e39dbb3a0f06fe95bbfd66e1648@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-04-30 18:42, Can Guo wrote: > On 2020-05-01 04:32, Bart Van Assche wrote: > > Has it been considered to test directly whether a SCSI device has been > > runtime suspended instead of relying on blk_queue_pm_only()? How about > > using pm_runtime_status_suspended() or adding a function in > > block/blk-pm.h that checks whether q->rpm_status == RPM_SUSPENDED? > > Yes, I used to make the patch like that way, and it also worked well, as > both ways are equal actually. I kinda like the current code because we > should be confident that after scsi_dev_type_resume() returns, pm_only > must be 0. Different reviewers may have different opinions, either way > works well anyways. Hi Can, Please note that this is not a matter of personal preferences of a reviewer but a matter of correctness. blk_queue_pm_only() does not only return a value > 0 if a SCSI device has been runtime suspended but also returns true if scsi_device_quiesce() was called for another reason. Hence my request to test the "runtime suspended" status directly and not to rely on blk_queue_pm_only(). Thanks, Bart.