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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 28 May 2020 12:28:46 +0200
Message-ID: <CAK8P3a3_5pHCc0WqDNt1Aim2M67cicyq27f0ggqPbJuu97i=Nw@mail.gmail.com>
Subject: Re: [PATCH 5/5] power: vexpress: make the reset driver a module
To:     Rob Herring <robh@kernel.org>
Cc:     Anders Roxell <anders.roxell@linaro.org>,
        SoC Team <soc@kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>
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On Wed, May 27, 2020 at 3:32 PM Rob Herring <robh@kernel.org> wrote:
>
> On Wed, May 27, 2020 at 5:26 AM Anders Roxell <anders.roxell@linaro.org> wrote:
> >
> > Today the vexpress power driver can only be builtin.  Rework so it's
> > possible for the vexpress power driver to be a module.
>
> This is the same incomplete patch I did[1]. As a module, it needs to
> clean-up everything probe did like overwriting global variables.
>
> Rob
>
> [1] https://lore.kernel.org/linux-arm-kernel/20200419170810.5738-5-robh@kernel.org/

Your version was actually broken because it allowed unloading the
driver again. The version that Anders sent is a bit better because it
explicitly forbids unloading by having a module_init but not module_exit
function, so as long as the .suppress_bind_attrs flag is set, this will
not crash the kernel.

It would be nice to have a .remove callback, but for the merge window
I'm happy with a patch that fixes the build regression.

        Arnd