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From:   Rob Herring <robh@kernel.org>
Date:   Thu, 1 Sep 2022 08:49:19 -0500
Message-ID: <CAL_Jsq+croyhct_=c3OGDnqd0N6GjL8aUgpD8D3YSDU3-VB1qw@mail.gmail.com>
Subject: Re: [PATCH] ARM: mmu: fix access to illegal address when using
 earlycon & memblock=debug
To:     Victor Hassan <victor@allwinnertech.com>
Cc:     Marek Szyprowski <m.szyprowski@samsung.com>,
        Russell King <linux@armlinux.org.uk>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        Linus Walleij <linus.walleij@linaro.org>,
        yanfei.xu@windriver.com, Ard Biesheuvel <ardb@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= <mirq-linux@rere.qmqm.pl>,
        Arnd Bergmann <arnd@arndb.de>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Thu, Sep 1, 2022 at 8:21 AM Rob Herring <robh@kernel.org> wrote:
>
> On Thu, Sep 1, 2022 at 7:54 AM Victor Hassan <victor@allwinnertech.com> wrote:
> >
> >
> >
> > On 2022/8/31 20:37, Victor Hassan wrote:
> > > On 8/31/2022 7:52 PM, Marek Szyprowski wrote:
> > >> Hi Victor,
> > >>
> > >> On 16.03.2022 03:33, Victor Hassan wrote:
> > >>> earlycon uses fixmap to create a memory map,
> > >>> So we need to close earlycon before closing fixmap,
> > >>> otherwise printk will access illegal addresses.
>
> How? Due to recent changes in how printk and the consoles work or just
> because create_mapping() can print? In the latter case, the only
> variable input is the phys address. I think most if not all prints
> cannot occur.

Ah, I missed the memblock debug part on the subject...

Rob