Re: [PATCH] mfd: intel_soc_pmic_crc: Use PWM_LOOKUP_WITH_MODULE() for the PWM lookup

From: Andy Shevchenko
Date: Sat May 25 2024 - 10:53:07 EST


On Thu, May 23, 2024 at 8:07 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> The primary use of the CRC PMIC's PWM is for LCD panel backlight
> control by the i915 driver.
>
> Due to its complexity the probe() function of the i915 driver does not
> support -EPROBE_DEFER handling. So far the pwm-crc driver must be built
> into the kernel to ensure that the pwm_get() done by the i915 driver
> succeeds at once (rather then returning -EPROBE_DEFER).
>
> But the PWM core can load the module from pwm_get() if a module-name is
> provided in the pwm_lookup associated with the consumer device.
>
> Switch to using PWM_LOOKUP_WITH_MODULE() for the lookup added for
> the Intel integrated GPU, so that the PWM core can load the module from
> pwm_get() as needed allowing the pwm-crc driver to be safely build as

built

> module.
>
> This has been successfully tested on an Asus T100TAM with pwm-crc
> build as module.

a module

Makes sense to me and it's good we allow better modularity as not all
x86-based products use Crystal Cove PMIC.
Reviewed-by: Andy Shevchenko <andy@xxxxxxxxxx>

Thanks for this good patch!

--
With Best Regards,
Andy Shevchenko