Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v3] scsi: ufs: Cleanup completed request without interrupt
 notification
To:     Avri Altman <Avri.Altman@wdc.com>,
        Stanley Chu <stanley.chu@mediatek.com>
Cc:     "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "alim.akhtar@samsung.com" <alim.akhtar@samsung.com>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "beanhuo@micron.com" <beanhuo@micron.com>,
        "asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
        "cang@codeaurora.org" <cang@codeaurora.org>,
        "matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
        "linux-mediatek@lists.infradead.org" 
        <linux-mediatek@lists.infradead.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kuohong.wang@mediatek.com" <kuohong.wang@mediatek.com>,
        "peter.wang@mediatek.com" <peter.wang@mediatek.com>,
        "chun-hung.wu@mediatek.com" <chun-hung.wu@mediatek.com>,
        "andy.teng@mediatek.com" <andy.teng@mediatek.com>,
        "chaotian.jing@mediatek.com" <chaotian.jing@mediatek.com>,
        "cc.chou@mediatek.com" <cc.chou@mediatek.com>
References: <20200706132113.21096-1-stanley.chu@mediatek.com>
 <3d509c4b-d66d-2a4a-5fbd-a50a0610ad31@acm.org>
 <1594607245.22878.8.camel@mtkswgap22>
 <SN6PR04MB46409838AE9D4BD63797E26DFC600@SN6PR04MB4640.namprd04.prod.outlook.com>
From:   Bart Van Assche <bvanassche@acm.org>
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: <912623e8-5915-8380-f39a-fac7b5868a6d@acm.org>
Date:   Tue, 14 Jul 2020 21:00:44 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <SN6PR04MB46409838AE9D4BD63797E26DFC600@SN6PR04MB4640.namprd04.prod.outlook.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

On 2020-07-13 01:10, Avri Altman wrote:
> Artificially injecting errors is a very common validation mechanism,
> Provided that you are not breaking anything of the upper-layers,
> Which I don't think you are doing.

Hi Avri,

My concern is that the code that is being added in the abort handler
sooner or later will evolve into a duplicate of the regular completion
path. Wouldn't it be better to poll for completions from the timeout
handler by calling ufshcd_transfer_req_compl() instead of duplicating
that function?

>>> In section 7.2.3 of the UFS specification I found the following about how
>>> to process request completions: "Software determines if new TRs have
>>> completed since step #2, by repeating one of the two methods described in
>>> step #2. If new TRs have completed, software repeats the sequence from
>>> step #3." Is such a loop perhaps missing from the Linux UFS driver?
>
> Could not find that citation.
> What version of the spec are you using?

That quote comes from the following document: "Universal Flash Storage
Host Controller Interface (UFSHCI); Version 2.1; JESD223C; (Revision of
JESD223B, September 2013); MARCH 2016".

Bart.