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Subject: Re: [PATCH 4.19 06/77] scsi: scsi_transport_spi: Set RQF_PM for
 domain validation commands
To:     Pavel Machek <pavel@ucw.cz>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Alan Stern <stern@rowland.harvard.edu>,
        James Bottomley <James.Bottomley@HansenPartnership.com>,
        Woody Suwalski <terraluna977@gmail.com>,
        Can Guo <cang@codeaurora.org>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Ming Lei <ming.lei@redhat.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Stan Johnson <userm57@yahoo.com>,
        Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Hannes Reinecke <hare@suse.de>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
References: <20210111130036.414620026@linuxfoundation.org>
 <20210111130036.711898511@linuxfoundation.org>
 <20210113114745.GA2843@duo.ucw.cz>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <e1fd4693-95f5-58c2-20c6-fbd96653edfe@acm.org>
Date:   Wed, 13 Jan 2021 17:43:18 -0800
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On 1/13/21 3:47 AM, Pavel Machek wrote:
>> From: Bart Van Assche <bvanassche@acm.org>
>>
>> [ Upstream commit cfefd9f8240a7b9fdd96fcd54cb029870b6d8d88 ]
>>
>> Disable runtime power management during domain validation. Since a later
>> patch removes RQF_PREEMPT, set RQF_PM for domain validation commands such
>> that these are executed in the quiesced SCSI device state.
> 
> This and "05/77] scsi: ide: Do not set the RQF_PREEMPT flag for" do
> not fix anything AFAICT. They are in series with other patches in
> 5.10, so they may make sense there, but I don't think we need them in
> 4.19.

Agreed. Please either backport the entire series of 8 patches or do not
backport any patch from that series. Selecting a subset of the patches
of that series is dangerous. As an example, applying patch 8/8 without
applying the prior patches from that series would break SCSI domain
validation. See also
https://lore.kernel.org/linux-scsi/20201209052951.16136-1-bvanassche@acm.org/

Thanks,

Bart.