Date: Wed, 20 Dec 2017 14:18:48 +0100
From: Lukasz Majewski <lukma@denx.de>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexander Sverdlin <alexander.sverdlin@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>, Arnd Bergmann <arndbergmann@gmail.com>,
        Hartley Sweeten <hsweeten@visionengravers.com>,
        Russell King <linux@armlinux.org.uk>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Olof Johansson <olof@lixom.net>
Subject: Re: [PATCH v5 0/4] ARM: ep93xx: ts72xx: Add support for BK3 board
Message-ID: <20171220141848.3f7c49c4@jawa>
In-Reply-To: <CACRpkdaAYLd6ZcBXQP_SfA1dTyyb4kjOpGoW5DUBgH_9pDDtQQ@mail.gmail.com>
References: <20171116232239.16823-1-lukma@denx.de>
        <20171211233625.5689-1-lukma@denx.de>
        <CACRpkdbCeBCENDcRcYBKTXVNz6H3t=WKHYP8Uf3WJ=Wvtib1Jg@mail.gmail.com>
        <1513153607.2439.2.camel@Nokia-N900>
        <20171213095257.5cf424fb@jawa>
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Hi Linus,

> On Wed, Dec 13, 2017 at 9:52 AM, Lukasz Majewski <lukma@denx.de>
> wrote:
> >> On Wed Dec 13 08:34:22 2017 Linus Walleij
> >> <linus.walleij@linaro.org> wrote: =20
> >> > On Tue, Dec 12, 2017 at 12:36 AM, Lukasz Majewski <lukma@denx.de>
> >> > wrote: Out of curiosity: Liebherr is obviously doing heavy-duty
> >> > industrial control systems. Likewise Hartley is doing similar
> >> > business over at Vision Engravings.
> >> >
> >> > Is the situation such that there is a whole bunch of industrial
> >> > systems out there, in active use and needing future upgrades,
> >> > that use the EP93xx? =20
> >>
> >> That's definitely the case. I'm as well aware of several thousands
> >> of industrial devices which are expected to run 24/7 for the next 5
> >> years at least. And they are updated from time to time. =20
> >
> > I can agree with this statement. =20
>=20
> OK I'm coloring this platform with a highlight for ARM32 maintenance.
>=20
> >> > Arnd has been nudging me to do DT conversion for EP93xx
> >> > so if there are many active industrial users of these
> >> > I should prioritize it, because these things have 20+ years
> >> > support cycles. =20
> >>
> >> I'm not sure how important or necessary at all is to change
> >> anything in these legacy platforms. =20
> >
> > +1 =20
>=20
> That is an understandable conservative stance.
>=20
> There is a fine line between "it works, don't touch it" and
> "modernize the ARM32 ecosystem".

There may be a more pragmatic reason. If those boards are deployed
(widely) in the industry - there may be a problem with re-validation of
the SW.

>=20
> There is a point where supporting old board files will stand in
> the way and cost a lot in maintenance (like moving drivers our
> of arch/arm, or modernizing misc subsystems). Then moving the
> platform over to device tree should be preferred.

With my limited experience - those platforms have more similarities to
x86. Multiplatform may be the goal here....

>=20
> > I'm using OE to build toolchain (SDK). I can confirm that gcc 7.2
> > works with it.
> >
> > And yes, armv4 support shall be preserved in GCC .... =20

I should have be more peculiar - this is armv4t (arm920t)

>=20
> Yes that is the same toochain I use.
>=20
> Yours,
> Linus Walleij


Best regards,

Lukasz Majewski

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