Re: [PATCH v4 1/8] pwm: Declare waveform stubs for when PWM is not reachable

[David Lechner <dlechner@baylibre.com>]

On 10/9/25 11:58 AM, Uwe Kleine-König wrote:
> Hello,
> 
> On Wed, Oct 08, 2025 at 10:49:44AM -0300, Marcelo Schmitt wrote:
>> Previously, the PWM waveform consumer API would not be declared if
>> CONFIG_PWM was not reachable. That caused kernel builds to fail if a
>> consumer driver was enabled but PWM disabled. Add stubs for PWM waveform
>> functions so client drivers that use, but don't depend on PWM, can build if
>> PWM is disabled.
>>
>> Fixes: 6c5126c6406d ("pwm: Provide new consumer API functions for waveforms")
>> Reported-by: kernel test robot <lkp@intel.com>
>> Closes: https://lore.kernel.org/oe-kbuild-all/202509272028.0zLNiR5w-lkp@intel.com/
>> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
>> ---
>> I've included this patch in this series because it should save us from being
>> notified by 0-day about the build failure this patch fixes. From contributor's
>> perspective, it's easier to have this patch together with the rest of ad4030
>> series. Though, no objection if kernel maintainers decide to pick it [1] through
>> the PWM tree.
>>
>> [1]: https://lore.kernel.org/linux-pwm/1ac0fc529e02744aacfcb9140ed597ff60886f39.1759873890.git.marcelo.schmitt@analog.com/
> 
> TL;DR: nack
> 
> I replied to the original submission about why this patch is wrong. See
> there for the details.
> 
> Best regards
> Uwe

If we want to avoid this patch, then it sounds like we should use:

#if IS_REACHABLE(CONFIG_PWM)

in the ADC driver around any PWM waveform code.