Re: [PATCH] serdev: fix builds with CONFIG_SERIAL_DEV_BUS=m

[Johan Hovold]

On Wed, Dec 18, 2019 at 09:38:42AM +0100, Uwe Kleine-König wrote:
> Commit 54edb425346a ("serdev: simplify Makefile") broke builds with
> serdev configured as module. I don't understand it completely yet, but
> it seems that
> 
> 	obj-$(CONFIG_SERIAL_DEV_BUS) += serdev/
> 
> in drivers/tty/Makefile with CONFIG_SERIAL_DEV_BUS=m doesn't result in
> code that is added using obj-y in drivers/tty/serdev/Makefile being
> compiled. So instead of dropping $(CONFIG_SERIAL_DEV_BUS) in serdev's
> Makefile, drop it in drivers/tty/Makefile.

Why not simply revert the offending patch? There are some dependencies
here related to how the tty layer is built. If you're still not certain
on why things broke, I suggest just reverting for now.

You can send a follow-up clean up if you think that's warranted instead.

> Fixes: 54edb425346a ("serdev: simplify Makefile")
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> ---
> Hello,
> 
> as Greg already added the offending patch to tty-next I assume it is
> frozen and cannot be dropped any more, so here is an incremental fix.

Johan