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=-2.3 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 2561BC433E0 for ; Sat, 16 May 2020 03:06:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2B152073E for ; Sat, 16 May 2020 03:06:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728017AbgEPDGd (ORCPT ); Fri, 15 May 2020 23:06:33 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:51739 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726247AbgEPDGc (ORCPT ); Fri, 15 May 2020 23:06:32 -0400 Received: by mail-pj1-f67.google.com with SMTP id mq3so1764968pjb.1; Fri, 15 May 2020 20:06:32 -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=T2GyJli/LtpjNMryaclGRF8nKqCQNV/l/DH3OGmd/9c=; b=M+FeyZMM6vVp00doQX97+0OwJO+20jTuZcbX0w2EaXGSWsfql/7T+pFUCqjVCdDq6l qYtFMAQ93dAdiweMOGOM9u8gqp893OmGx/XVz9e1FG6sq3J+dVBYMh7CHL+n+S57/tGz H3cHmXDDYf33HGNVOIHaGi5mCaxEz1MsdfO3J2TrsmHfxIVswYeiq3vgYJZXvWKivqLR o6/NqcTCRDG3Z5IzKeP2hc9gjT/ogl+xn0FPxTfmMVMVAhBNTv6VrLrXZ97leHKaHDXg GR7iHRLO1nKhlrxgE2JiZRYNTLcRYilzdLUaI8Z0KjAGYzCaogDnRwsYFukHx5dTHUkr ySTw== X-Gm-Message-State: AOAM533d6SYs9Hgxttv01cL4e4m4nBJ2OsBHf2YQ7oHMNd7bTEUyr7k2 YB/HwLrbJz+1vjyp9gWIwPE= X-Google-Smtp-Source: ABdhPJx+vns/ssIkJi4jyZILzl09L0c7z3Gfq+MJqyh+rsrNcXyD1wZtZWFUhveEu/tBDZ8XYMo7SA== X-Received: by 2002:a17:902:9044:: with SMTP id w4mr6607162plz.83.1589598391314; Fri, 15 May 2020 20:06:31 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:f99a:ee92:9332:42a? ([2601:647:4000:d7:f99a:ee92:9332:42a]) by smtp.gmail.com with ESMTPSA id z7sm2968082pff.47.2020.05.15.20.06.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 May 2020 20:06:30 -0700 (PDT) Subject: Re: [RFC PATCH 09/13] scsi: ufshpb: Add response API To: Avri Altman , "James E . J . Bottomley" , "Martin K . Petersen" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: alim.akhtar@samsung.com, asutoshd@codeaurora.org, Zang Leigang , Avi Shchislowski , Bean Huo , cang@codeaurora.org, stanley.chu@mediatek.com, MOHAMMED RAFIQ KAMAL BASHA , Sang-yoon Oh , yongmyung lee , Jinyoung CHOI References: <1589538614-24048-1-git-send-email-avri.altman@wdc.com> <1589538614-24048-10-git-send-email-avri.altman@wdc.com> 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: <9619597b-3a3e-e67c-5afa-cebf03cc678b@acm.org> Date: Fri, 15 May 2020 20:06:28 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <1589538614-24048-10-git-send-email-avri.altman@wdc.com> 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 2020-05-15 03:30, Avri Altman wrote: > +#define RSP_DATA_SEG_LEN (sizeof(struct ufshpb_sense_data)) The name of this macro is almost as long as the expression it replaces. It may make the code easier to read by dropping this macro and using the sizeof() expression directly. > + struct tasklet_struct rsp_tasklet; Why a tasklet instead of e.g. a work_struct? Tasklets can cause nasty problems, e.g. CPU lockup complaints if too much work is done in tasklet context. > +static void ufshpb_dh_notify(struct ufshpb_lun *hpb, > + struct ufshpb_sense_data *sense) > +{ > + struct ufs_hba *hba = shost_priv(hpb->sdev->host); > + > + spin_lock(hba->host->host_lock); > + > + if (scsi_device_get(hpb->sdev)) { > + spin_unlock(hba->host->host_lock); > + return; > + } > + > + scsi_dh_set_params(hpb->sdev->request_queue, (const char *)sense); > + > + scsi_device_put(hpb->sdev); > + > + spin_unlock(hba->host->host_lock); > +} To me this looks like slight abuse of the scsi_dh_set_params() function. The documentation of that function mentions clearly that the second argument is an ASCII string and not e.g. sense data. Has this driver been tested on a system with lockdep enabled? I don't think that it is acceptable to use spin_lock() in tasklet context. > +static void ufshpb_tasklet_fn(unsigned long priv) > +{ > + struct ufshpb_lun *hpb = (struct ufshpb_lun *)priv; > + struct ufshpb_rsp_element *rsp_elem = NULL; > + unsigned long flags; > + > + while (1) { > + spin_lock_irqsave(&hpb->rsp_list_lock, flags); > + rsp_elem = ufshpb_get_rsp_elem(hpb, &hpb->lh_rsp); > + spin_unlock_irqrestore(&hpb->rsp_list_lock, flags); > + > + if (!rsp_elem) > + return; > + > + ufshpb_dh_notify(hpb, &rsp_elem->sense_data); > + > + spin_lock_irqsave(&hpb->rsp_list_lock, flags); > + list_add_tail(&rsp_elem->list, &hpb->lh_rsp_free); > + spin_unlock_irqrestore(&hpb->rsp_list_lock, flags); > + } > +} Please schedule work instead of using tasklet context. Thanks, Bart.