Re: [PATCH] gpiolib: Avoid side effects in gpio_is_visible()

From: Linus Walleij
Date: Mon May 29 2023 - 05:08:19 EST


On Wed, May 17, 2023 at 12:19 AM Chris Packham
<Chris.Packham@xxxxxxxxxxxxxxxxxxx> wrote:
> On 17/05/23 01:57, Linus Walleij wrote:
> > On Mon, May 15, 2023 at 12:27 AM Chris Packham
> > <Chris.Packham@xxxxxxxxxxxxxxxxxxx> wrote:

> >> The crux of the problem is that the irq_desc is created when it hasn't
> >> been requested.

> > The right solution to me seems to be to not use gpiod_export()
> > and not use sysfs TBH.
>
> That's not really a feasible solution. I'm dealing with application code
> that has been happily using the sysfs interface for many years.

I wonder how many years.

The GPIO sysfs has been deprecated for seven years:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/Documentation/ABI/obsolete/sysfs-gpio?id=fe95046e960b4b76e73dc1486955d93f47276134

My fear is that deprecation is ignored and people still develop stuff
like this ignoring the fact that the ABI is deprecated.

Yours,
Linus Walleij