Date:   Tue, 4 Jan 2022 12:20:26 -0600
From:   Patrick Williams <patrick@stwcx.xyz>
To:     Miquel Raynal <miquel.raynal@bootlin.com>
Cc:     Pratyush Yadav <p.yadav@ti.com>, Joel Stanley <joel@jms.id.au>,
        Tudor Ambarus <tudor.ambarus@microchip.com>,
        Michael Walle <michael@walle.cc>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Andrew Jeffery <andrew@aj.id.au>,
        Potin Lai <potin.lai@quantatw.com>,
        linux-mtd@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mtd: aspeed-smc: improve probe resilience
Message-ID: <YdSP6tKyQ2ZRUC+2@heinlein>
References: <20211229143334.297305-1-patrick@stwcx.xyz>
 <20211229173411.l2bipmi4x3arqjoo@ti.com>
 <Yc3Qav+ULNdF5zRT@heinlein>
 <20211231102623.izaqlzjvracbbgmp@ti.com>
 <20220103171721.46c8e697@xps13>
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Hi Miquel,

On Mon, Jan 03, 2022 at 05:17:21PM +0100, Miquel Raynal wrote:

> > I am fine with taking in bug fixes but no longer want to take in any ne=
w=20
> > features. My main intention was to nudge you to convert it to SPI MEM=
=20
> > regardless of whether this is a bug fix or a new feature, because=20
> > eventually we want to get rid of drivers/mtd/spi-nor/controllers/ and=
=20
> > the API that comes along with it.
>=20
> I totally agree with Pratyush here, we no longer want to support the
> spi-nor controller API so if, as you say, there are boards failing
> in the field, it means there are still users and these users must be
> warned that at some point we might discontinue the support of these
> drivers if it becomes too painful.
>

Your response here makes it seem like you don't realize the scope of this
driver.  There are probably, by my estimates, on the order of 10s of millio=
ns of
deployed systems using this driver in the world.  The vast majority of serv=
ers
in the world use an AST2400, AST2500, or AST2600 chip, which needs this dri=
ver
in order access its own flash storage device.  Both OpenBMC and most of the
proprietary alternatives use this driver.

The company I work for has a LOT of systems using this code.  After I made =
this
fix, for a new design being developed, it was pointed out to me that our OD=
M ran
into this problem a few years ago and we've been really bad about upstreami=
ng
those fixes.  For this new system I'm trying to keep us on top of all
upstreaming efforts.

To me the inability to access your own storage, resulting in a kernel panic=
, is
a pretty serious issue.  Bug or feature I guess is always in the eye of the
beholder though.  I think this is pretty valuable to get in, from an impact
standpoint, and pretty minimal in terms of maintenance efforts on the
maintainers part.

I had an offline discussion with someone who knew more history on this driv=
er.
My understanding is that the linux-aspeed team is aware of this being depre=
cated
but that there was some missing support for interface training that nobody =
has
gotten around to write?  If that is the case this really isn't even a "simp=
le"
port to a new API at this point.

--=20
Patrick Williams

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