On Thu, Oct 20, 2022 at 11:27:22AM +0800, Zhang Xiaoxu wrote:
> When set CONFIG_SERIAL_EARLYCON=y and CONFIG_SERIAL_CORE=m, there is
> a compile error as below:
>
> ld: vmlinux.o: in function `parse_options.constprop.0':
> earlycon.c:(.init.text+0xba5a3): undefined reference to `uart_parse_earlycon'
>
> Since the SERIAL_EARLYCON use 'uart_parse_earlycon' which defined in
> SERIAL_CORE, so should select rather than depends on.
No, please try to never use "select".
>
> Fixes: 9aac5887595b ("tty/serial: add generic serial earlycon")
So this has been a problem for a very very long time and never been
seen until now? That feels wrong, what changed to cause this to not
ever be hit before with all of the tens of thousands of random configs
that have been built since this very old kernel?
thanks,
greg k-h
