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Date:   Fri, 21 Oct 2022 23:55:07 +0200
From:   Christian Marangi <ansuelsmth@gmail.com>
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     Geert Uytterhoeven <geert+renesas@glider.be>,
        Russell King <linux@armlinux.org.uk>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Ard Biesheuvel <ardb@kernel.org>,
        "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
        Nick Hawkins <nick.hawkins@hpe.com>,
        John Crispin <john@phrozen.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] ARM: mach-qcom: fix support for ipq806x
References: <20221021181016.14740-1-ansuelsmth@gmail.com>
 <CACRpkdbfvr1pkVb3XhBZLnmn7vy3XyzavwVjW_VmFKTdh3LABQ@mail.gmail.com>
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On Fri, Oct 21, 2022 at 11:44:56PM +0200, Linus Walleij wrote:
> On Fri, Oct 21, 2022 at 8:10 PM Christian Marangi <ansuelsmth@gmail.com> wrote:
> 
> > Add a specific config flag for Qcom IPQ806x as this SoC can't use
> > AUTO_ZRELADDR and require the PHYS_OFFSET set to 0x42000000.
> >
> > This is needed as some legacy board (or some wrongly configured
> > bootloader) pass the wrong memory map and doesn't exclude the first
> > ~20MB of RAM reserved for the hardware network accellerators.
> >
> > With this change we can correctly support each board and prevent any
> > kind of misconfiguration done by the OEM.
> >
> > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> 
> I had exactly this problem with the APQ8060 as well, then my problem
> went away. I was under the impression that this was solved.
> 
> Is it not possible to use Geert's linux,usable-memory-range in
> the chosen node to make the kernel stay off the memory?
> (See examples by grep usable-memory in the kernel.)
> 

Hi,
just to confirm this is one of the example you are suggesting?

chosen {
		bootargs = "console=ttyS0,115200 earlycon";
		stdout-path = "serial0:115200n8";
		linux,usable-memory-range = <0x80200000 0x1fe00000>;
	};

Main problem here is that uboot in some case doesn't support dt and pass
wrong ATAGS (with the memory not reserved) and AUTO_ZRELADDR calculate
the wrong addr I assume?

I will test the usable-memory-range but isn't the same of declaring
reserved space in the dts? Or the zimage decompressor checks
linux,usable-memory-range bypassing atags?

-- 
	Ansuel