Re: [RFC] gpio: consumer: Remove WARN_ON(1) when GPIOLIB is disabled

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Thu, Jul 20, 2017 at 1:08 AM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:

> Hmm, I did not realize that GPIO API allowed calls with NULL desc and
> they would be silently accepted and return 0... Not sure if that is the
> best way for the subsystem to behave, but Linus is the boss ;)

NULL gpiods are supported for
gpiod_get_[index_]optional() usecasese only.

See commit:
commit 54d77198fdfbc4f0fe11b4252c1d9c97d51a3264
"gpio: bail out silently on NULL descriptors"

> Maybe check for NULL explicitly and keep warning if !NULL is passed?

A better solution is maybe if gpiod_get_[index_]optional() could
return something akin to a dummy regulator if the GPIO is not
there?

Then we can stop allowing NULL gpiods.

Optional regulators also have some tricksy corner cases like this...

Yours,
Linus Walleij
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