Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <2677b02e-b2a3-7c79-2e62-acf1acbc8ff0@acm.org>
Date:   Mon, 6 Jun 2022 06:16:20 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.8.0
Subject: Re: [RESEND PATCH] scsi: ufs: sysfs: support writing boot_lun attr
Content-Language: en-US
To:     Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Avri Altman <Avri.Altman@wdc.com>,
        Caleb Connolly <caleb.connolly@linaro.org>,
        "a5b6@riseup.net" <a5b6@riseup.net>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc:     "~postmarketos/upstreaming@lists.sr.ht" 
        <~postmarketos/upstreaming@lists.sr.ht>,
        "phone-devel@vger.kernel.org" <phone-devel@vger.kernel.org>
References: <20220525164013.93748-1-a5b6@riseup.net>
 <DM6PR04MB65750969ACD36EEEB48374DFFCD69@DM6PR04MB6575.namprd04.prod.outlook.com>
 <8d25171a-5d86-9acc-0f94-1a3c6efdb360@riseup.net>
 <DM6PR04MB65752422396C86EAD4591701FCD89@DM6PR04MB6575.namprd04.prod.outlook.com>
 <a7f46ad1-6d9e-a38e-31cc-29fddfa2b496@linaro.org>
 <DM6PR04MB65751A3B1D0BA4467CADDA93FCDF9@DM6PR04MB6575.namprd04.prod.outlook.com>
 <a4746c67-fa74-8af1-3f2d-7853e9fae8a6@acm.org>
 <3c400db6-d251-c4bd-b019-b9dc1d807212@opensource.wdc.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <3c400db6-d251-c4bd-b019-b9dc1d807212@opensource.wdc.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 6/5/22 19:48, Damien Le Moal wrote:
> On 6/5/22 12:55, Bart Van Assche wrote:
>> On 6/1/22 10:05, Avri Altman wrote:
>>> As a design rule, sysfs attribute files should not be used to make
>>> persistent modifications to a device configuration. This rule applies
>>> to all subsystems and ufs is no different.
>>
>> Hmm ... where does that rule come from? I can't find it in
>> Documentation/admin-guide/sysfs-rules.rst. Did I perhaps overlook something?
> 
> I am not aware of any writable sysfs attribute file that can be used to
> make persistent device configuration changes, at least in storage area.
> I know of plenty that do change a device setting, but without saving this
> setting to maintain it across power cycles. Do you know of any such
> attribute ? I was under the impression that sysfs should not be used to
> persistently reconfigure a device...

I don't think the above is sufficient as an argument to reject a new 
patch that introduces a sysfs attribute that changes the device 
configuration.

Thanks,

Bart.