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References: <20211206113828.42523-1-stephan@gerhold.net>
In-Reply-To: <20211206113828.42523-1-stephan@gerhold.net>
From:   Fabio Estevam <festevam@gmail.com>
Date:   Mon, 6 Dec 2021 08:58:13 -0300
Message-ID: <CAOMZO5A09BDOuEbmWJVD_5d=E6wSf3YcCf0=EkB-B2wWR0r52Q@mail.gmail.com>
Subject: Re: [PATCH] soc: imx: Register SoC device only on i.MX boards
To:     Stephan Gerhold <stephan@gerhold.net>
Cc:     Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        NXP Linux Team <linux-imx@nxp.com>,
        =?UTF-8?Q?Jonathan_Neusch=C3=A4fer?= <j.neuschaefer@gmx.net>,
        Sebastian Reichel <sebastian.reichel@collabora.com>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Peng Fan <peng.fan@nxp.com>, Arnd Bergmann <arnd@arndb.de>
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On Mon, Dec 6, 2021 at 8:40 AM Stephan Gerhold <stephan@gerhold.net> wrote:
>
> At the moment, using the ARM32 multi_v7_defconfig always results in two
> SoCs being exposed in sysfs. This is wrong, as far as I'm aware the
> Qualcomm DragonBoard 410c does not actually make use of a i.MX SoC. :)
>
>   qcom-db410c:/sys/devices/soc0$ grep . *
>   family:Freescale i.MX
>   machine:Qualcomm Technologies, Inc. APQ 8016 SBC
>   revision:0.0
>   serial_number:0000000000000000
>   soc_id:Unknown
>
>   qcom-db410c:/sys/devices/soc1$ grep . *
>   family:Snapdragon
>   machine:APQ8016
>   ...
>
> This happens because imx_soc_device_init() registers the soc device
> unconditionally, even when running on devices that do not make use of i.MX.
> Arnd already reported this more than a year ago and even suggested a fix
> similar to this commit, but for some reason it was never submitted.
>
> Fix it by checking if the "__mxc_cpu_type" variable was actually
> initialized by earlier platform code. On devices without i.MX it will
> simply stay 0.
>
> Cc: Peng Fan <peng.fan@nxp.com>
> Fixes: d2199b34871b ("ARM: imx: use device_initcall for imx_soc_device_init")
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Link: https://lore.kernel.org/r/CAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSYNjFeuw@mail.gmail.com/
> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>

Reviewed-by: Fabio Estevam <festevam@gmail.com>