Re: [PATCH 1/4] gpiolib: add opt-out for existing drivers with static GPIO base

From: Andy Shevchenko
Date: Tue Jan 14 2025 - 04:50:02 EST


On Tue, Jan 14, 2025 at 12:20 AM Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote:
>
> Some drivers have had deterministic GPIO numbering for most of
> their existence, e.g. the i.MX GPIO since commit 7e6086d9e54a
> ("gpio/mxc: specify gpio base for device tree probe"), more than
> 12 years ago.
>
> Reverting this to dynamically numbered will break existing setups in
> the worst manner possible: The build will succeed, the kernel will not
> print warnings, but users will find their devices essentially toggling
> GPIOs at random with the potential of permanent damage.
>
> As these concerns won't go away until the sysfs interface is removed,
> let's add a new struct gpio_chip::legacy_static_base member that can be
> used by existing drivers that have been grandfathered in to suppress
> the warning currently being printed:
>
> gpio gpiochip0: Static allocation of GPIO base is deprecated,
> use dynamic allocation.

Warning is harmless and still a good reminder for the stuff that needs
more love.
NAK.

--
With Best Regards,
Andy Shevchenko