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Message-ID: <b532e50f-7aa0-5ac3-c7a6-6a43ab9c1bc9@acm.org>
Date:   Tue, 16 Aug 2022 11:05:27 -0700
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Subject: Re: [PATCH 5.19 0784/1157] scsi: sd: Rework asynchronous resume
 support
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To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Cc:     stable@vger.kernel.org, Ming Lei <ming.lei@redhat.com>,
        Hannes Reinecke <hare@suse.de>,
        John Garry <john.garry@huawei.com>, ericspero@icloud.com,
        jason600.groome@gmail.com,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
References: <20220815180439.416659447@linuxfoundation.org>
 <20220815180510.851284927@linuxfoundation.org>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20220815180510.851284927@linuxfoundation.org>
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On 8/15/22 11:02, Greg Kroah-Hartman wrote:
> From: Bart Van Assche <bvanassche@acm.org>
> 
> [ Upstream commit 88f1669019bd62b3009a3cebf772fbaaa21b9f38 ]
> 
> For some technologies, e.g. an ATA bus, resuming can take multiple
> seconds. Waiting for resume to finish can cause a very noticeable delay.
> Hence this commit that restores the behavior from before "scsi: core: pm:
> Rely on the device driver core for async power management" for most SCSI
> devices.
> 
> This commit introduces a behavior change: if the START command fails, do
> not consider this as a SCSI disk resume failure.
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=215880
> Link: https://lore.kernel.org/r/20220630195703.10155-3-bvanassche@acm.org
> Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")

Hi Greg,

It has been reported that this patch causes a regression, namely disks 
not coming back after a resume. That issue is worse than the issue fixed 
by this patch - eliminating a delay. Please drop this patch from the 
stable tree.

A revert of this patch has been posted on the linux-scsi mailing list. 
See also 
https://lore.kernel.org/linux-scsi/8a83665a-1951-a326-f930-8fcbb0c4dd9a@huawei.com/.

Thanks,

Bart.