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References: <20191111133421.14390-1-anup.patel@wdc.com> <alpine.DEB.2.21.999.1911111705350.30304@utopia.booyaka.com>
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From:   Anup Patel <anup@brainfault.org>
Date:   Tue, 12 Nov 2019 09:49:38 +0530
Message-ID: <CAAhSdy28n=XkhcZC2=7L8YZyxa5yJ+CUso_s7kK5FacUQM6tMA@mail.gmail.com>
Subject: Re: [PATCH] RISC-V: Enable SYSCON reboot and poweroff drivers
To:     Paul Walmsley <paul@pwsan.com>
Cc:     Anup Patel <Anup.Patel@wdc.com>,
        Palmer Dabbelt <palmer@sifive.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Atish Patra <Atish.Patra@wdc.com>,
        Alistair Francis <Alistair.Francis@wdc.com>,
        "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>,
        Christoph Hellwig <hch@lst.de>
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On Mon, Nov 11, 2019 at 10:36 PM Paul Walmsley <paul@pwsan.com> wrote:
>
> On Mon, 11 Nov 2019, Anup Patel wrote:
>
> > We can use SYSCON reboot and poweroff drivers for the
> > SiFive test device found on QEMU virt machine and SiFive
> > SOCs.
> >
> > This patch enables SYSCON reboot and poweroff drivers
> > in RV64 and RV32 defconfigs.
> >
> > Signed-off-by: Anup Patel <anup.patel@wdc.com>
>
> I'd much prefer Christoph's driver, once it's fixed up per my earlier
> comments.  This business with writing random registers based on what's in
> the DT data has always been a bad idea.

Like mentioned in other email thread, we are not writing random
date to registers. In fact, we are describing Reboot and Poweroff
mechanism in DT using SYSCON Reboot and Poweroff DT nodes.

This is not a new approach. It has been used by a variety of SOCs
in past.

Regards,
Anup