Re: [PATCH v2 11/11] mtd: new support oops logger based on pstore/blk

[Miquel Raynal <miquel.raynal@bootlin.com>]

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