Re: [PATCH v1 1/1] serial: 8250_ce4100: Fix CONFIG_SERIAL_8250=n build

From: Jiri Slaby
Date: Wed Jul 16 2025 - 06:44:02 EST


On 16. 07. 25, 12:28, Andy Shevchenko wrote:
On Wed, Jul 16, 2025 at 12:14:23PM +0200, Jiri Slaby wrote:
On 16. 07. 25, 11:44, Andy Shevchenko wrote:
On i386, when

CONFIG_X86_INTEL_CE=y
# CONFIG_SERIAL_8250 is not set

will try to compile the driver and use the stub simultaneously.
This breaks the build. Fix it by making sure that the driver
compiles only when CONFIG_SERIAL_8250 is also enabled.

...

+ifneq ($(CONFIG_SERIAL_8250),)

Why not ifdef CONFIG_SERIAL_8250 then?

$ git grep -n '^ifn\?eq .*CONFIG_' | wc -l
427
$ git grep -n '^ifdef CONFIG_' | wc -l
431

Is there a preference in serial drivers?

The simpler to read/understand -- the latter.

Also, what happens if 8250=m and X86_INTEL_CE=y?

So, in such a case if somebody wants to use UART, it will go crazy due to
missed workaround applied. BUT, this is preexisted issue and not related
(directly) to this fix. Perhaps we can combine both with

ifeq ($(CONFIG_SERIAL_8250),y)

and add two Fixes tags.

+1 makes sense to me. Or introduce a Kconfig entry to handle the deps...

thanks,
--
js
suse labs