Re: [PATCH v8 2/3] pinctrl: pinctrl-microchip-sgpio: Add pinctrl driver for Microsemi Serial GPIO

From: Alexandre Belloni
Date: Mon Nov 09 2020 - 11:22:16 EST


On 09/11/2020 18:15:30+0200, Andy Shevchenko wrote:
> > > > Userspace should never have to
> > > > handle gpios directly or you are doing something wrong.
> > >
> > > This is true, but check how error codes are propagated to the user space.
> > >
> >
> > your point is to remove an error message because the error may be
> > propagated to userspace. My point is that userspace should never use
> > gpios and the kernel has to be the consumer.
>
> Tell this to plenty of users of old sysfs interface and to libgpiod ones.

Exactly, that is what I'm telling to them.

> If what you are saying had been true, we would have never had the new
> ABI for GPIOs.
>
> > I don't see how your answer
> > is relevant here.
>
> I have an opposite opinion.
>
> > Did you already check all the call sites from the
> > kernel too?
>
> If you think we have to print a message on each possible error case
> (but not always the one) we will get lost in the messages disaster and
> dmesg overflow.
> It is consumer who should decide if the setting is critical or not to
> be printed to user.
>

This is the valid reason and as you can see, it has nothing to do with
userspace.

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com