Re: [PATCH 2/2] gpiolib: cdev: export the consumer's PID

From: Bartosz Golaszewski
Date: Tue Sep 13 2022 - 15:36:48 EST


On Tue, Sep 13, 2022 at 7:09 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Wed, Sep 14, 2022 at 12:17:39AM +0800, Kent Gibson wrote:
> > On Tue, Sep 13, 2022 at 05:58:32PM +0200, Bartosz Golaszewski wrote:
> > > On Tue, Sep 13, 2022 at 4:55 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>
> ...
>
> > > We'd need of course first expose that info like:
> > >
> > > gpio chip:gpiochip2 lines:0,3,4,7
> > >
> > > Does that make sense?
> >
> > Makes sense to me, though I don't claim to know anything about fdinfo
> > field formatting.
> >
> > e.g. I also see fdinfo fields like this:
> >
> > eventfd-count: 0
> > eventfd-id: 1
> >
> > so
> >
> > gpio-chip: gpiochip2
> > gpio-lines: 0,3,4,7
> >
> > might be ok too.
>
> Always think about two or more GPIO chips in the same process with 1 or more
> lines requested from each of them.
>

That is fine because every file descriptor has its own fdinfo entry
and so one entry can only contain information about a single request.

Bart