On Thu, Oct 20, 2022 at 09:20:24PM +0800, zhangxiaoxu (A) wrote:
>
>
> On 2022/10/20 13:04, Greg KH wrote:
> > 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?
> >
> Yes, 0fb9342d06b0 ("tty: serial: earlycon dependency") already fix the
> same issue with add "depends on SERIAL_CORE".
>
> But there are some other scenarios can trigger the same issue.
>
> Use the config file in the bugzilla can reproduce the problem.
> https://bugzilla.kernel.org/show_bug.cgi?id=216611
>
> Bisect with this config, find out the following commit introduce the issue:
> cdcc41a256efe8 ("tty: serial: Kconfig: Allow SERIAL_QCOM_GENI_CONSOLE to be enabled if SERIAL_QCOM_GENI is a module")
>
> config SERIAL_QCOM_GENI
> tristate "QCOM on-chip GENI based serial port support"
> depends on ARCH_QCOM || COMPILE_TEST
> depends on QCOM_GENI_SE
> select SERIAL_CORE
>
> config SERIAL_QCOM_GENI_CONSOLE
> bool "QCOM GENI Serial Console support"
> - depends on SERIAL_QCOM_GENI=y
> + depends on SERIAL_QCOM_GENI
> select SERIAL_CORE_CONSOLE
> select SERIAL_EARLYCON
> help
> Serial console driver for Qualcomm Technologies Inc's GENI based
> QUP hardware.
Then this is an issue with that driver Kconfig options, not with the tty
core options. Please fix it up there.
thanks,
greg k-h
