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Date:   Tue, 18 Feb 2020 11:34:49 +0100
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     WeiXiong Liao <liaoweixiong@allwinnertech.com>
Cc:     Kees Cook <keescook@chromium.org>,
        Anton Vorontsov <anton@enomsg.org>,
        Colin Cross <ccross@android.com>,
        Tony Luck <tony.luck@intel.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Rob Herring <robh@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mtd@lists.infradead.org
Subject: Re: [PATCH v2 11/11] mtd: new support oops logger based on
 pstore/blk
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        <1581078355-19647-12-git-send-email-liaoweixiong@allwinnertech.com>
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Hi WeiXiong,

WeiXiong Liao <liaoweixiong@allwinnertech.com> wrote on Fri,  7 Feb
2020 20:25:55 +0800:

> It's the last one of a series of patches for adaptive to MTD device.
> 
> The mtdpstore is similar to mtdoops but more powerful. It bases on
> pstore/blk, aims to store panic and oops logs to a flash partition,
> where it can be read back as files after mounting pstore filesystem.
> 
> The pstore/blk and blkoops, a wrapper for pstore/blk, are designed for
> block device at the very beginning, but now, compatible to not only
> block device. After this series of patches, pstore/blk can also work
> for MTD device. To make it work, 'blkdev' on kconfig or module
> parameter of blkoops should be set as mtd device name or mtd number.
> See more about pstore/blk and blkoops on:
>     Documentation/admin-guide/pstore-block.rst
> 
> Why do we need mtdpstore?
> 1. repetitive jobs between pstore and mtdoops
>    Both of pstore and mtdoops do the same jobs that store panic/oops log.
>    They have much similar logic that register to kmsg dumper and store
>    log to several chunks one by one.
> 2. do what a driver should do
>    To me, a driver should provide methods instead of policies. What MTD
>    should do is to provide read/write/erase operations, geting rid of codes
>    about chunk management, kmsg dumper and configuration.
> 3. enhanced feature
>    Not only store log, but also show it as files.
>    Not only log, but also trigger time and trigger count.
>    Not only panic/oops log, but also log recorder for pmsg, console and
>    ftrace in the future.
> 
> Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>

Richard, your PoV on this is welcome.

I suppose this patch depends on the others to work correctly so maybe
we should wait the next release before applying it.

Thanks,
Miquèl