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

[Jiri Slaby <jirislaby@kernel.org>]

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