RE: [PATCH V3 1/1] nvme: Add quirk for LiteON CL1 devices running FW 220TQ,22001

[Gloria Tsai]

Rephrased the problem description here,
When host issue shutdown + D3hot in suspend, NVMe drive might have chance choosing wrong pointer which has already been used by GC then cause over program.
Do GC before shutdown -> delete IO Q -> shutdown from host -> breakup GC -> D3hot -> enter PS4 -> have a chance swap block -> use wrong pointer on device SRAM -> over program
The issue only happens in simple suspend (shutdown+D3hot) with specific FW on Kahoku board.


Regards,
Gloria Tsai
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-----Original Message-----
From: Christoph Hellwig <hch@xxxxxx> 
Sent: Tuesday, November 3, 2020 2:13 AM
To: Jongpil Jung <jongpuls@xxxxxxxxx>
Cc: Keith Busch <kbusch@xxxxxxxxxx>; Jens Axboe <axboe@xxxxxx>; Christoph Hellwig <hch@xxxxxx>; Sagi Grimberg <sagi@xxxxxxxxxxx>; linux-nvme@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Gloria Tsai <Gloria.Tsai@xxxxxxxxx>; jongpil19.jung@xxxxxxxxxxx; jongheony.kim@xxxxxxxxxxx; dj54.sohn@xxxxxxxxxxx
Subject: Re: [PATCH V3 1/1] nvme: Add quirk for LiteON CL1 devices running FW 220TQ,22001



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On Thu, Oct 29, 2020 at 03:55:29PM +0100, Christoph Hellwig wrote:
> I'm still worried about this.
>
> If power state based suspend does always work despite a HMB and is 
> preferred for the specific Google board we should have purely a DMI 
> based quirk for the board independent of the NVMe controller used with 
> it.
>
> But if these LiteON devices can't properly handle nvme_dev_disable 
> calls we have much deeper problems, because it can be called in all 
> kinds of places, including suspending when not on this specific board.
>
> That being said, I still really do not understand this sentence and 
> thus the problem at all:
>
> > When NVMe device receive D3hot from host, NVMe firmware will do 
> > garbage collection. While NVMe device do Garbage collection, 
> > firmware has chance to going incorrect address.

Any progress in describing the problem a little better?