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

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Mon, Jan 13, 2025 at 11:19 PM Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote:

> 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:

I think entire drivers, pertaining to in worst case several generations
of SoCs is not the way to approach this. It could be a SoC or, more
likely, single systems using a SoC, that has a problem with this.

If you want to safeguard this I would use some code loop in the
gpiolib(-sysfs) that looks at of_machine_is_compatible("foo,bar-machine")
to match the top-level compatible for known problematic machines
so we can be fine-grained of this so when that machines retires
the driver can start using dynamic GPIO number allotment.

Yours,
Linus Walleij