[PATCH] soc: imx: Register SoC device only on i.MX boards

[Fabio Estevam]

On Mon, Dec 6, 2021 at 8:40 AM Stephan Gerhold <stephan at 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 at nxp.com>
> Fixes: d2199b34871b ("ARM: imx: use device_initcall for imx_soc_device_init")
> Reported-by: Arnd Bergmann <arnd at arndb.de>
> Link: https://lore.kernel.org/r/CAK8P3a0hxO1TmK6oOMQ70AHSWJnP_CAq57YMOutrxkSYNjFeuw@mail.gmail.com/
> Signed-off-by: Stephan Gerhold <stephan at gerhold.net>

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