Replying to self so Bartosz don't have to tell me off...

On Wed, Oct 1, 2025 at 10:49 AM Linus Walleij [off-list ref] wrote:

and every GPIO access on every system will be proxied
and then this better be fast.

What about I read the code before I talk :/

Inspecting patch 4/9 it is clear that only GPIOs that actually
need to be proxied are proxied.

Two things come to mind, and I bet you have thought of
them already:

1. Footprint: all systems using regulators will now have
   to compile in all this code as well.

This still holds. It could be a concern if it's a lot of code.

2. Performance, I didn't quite get it if every GPIO on the
  system will be proxied through a layer of indirection
  if you select HAVE_SHARED_GPIOS
  but that would not be good, since some users are in
  fastpath such as IRQ handlers, and the old way of
  sharing GPIOs would just affect pins that are actually
  shared.

It is clear from patch 4/9 that this only affects GPIOs
that are actually shared, and those tend to not be
performance-critical so this concern is moot.

Yours,
Linus Walleij