Re: [libgpiod][PATCH 0/5] core: provide information about the parent chip in line requests

[Kent Gibson <warthog618@xxxxxxxxx>]

On Thu, Jul 20, 2023 at 09:59:00AM +0200, Bartosz Golaszewski wrote:
> On Thu, Jul 20, 2023 at 5:27 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:
> >
> > On Wed, Jul 19, 2023 at 09:20:52PM +0200, Bartosz Golaszewski wrote:
> > > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> > >
> > > While working on the DBus API, it occurred to me that while we can obtain
> > > the list of requested offsets from a line request, this information lacks
> > > context if we cannot get any information about the parent chip on which
> > > the request was made.
> > >
> > > We cannot reference the chip in any way as its lifetime is disconnected
> > > from the request but we can at least provide the path to the character
> > > device used to open it as a way of providing some context for the offsets.
> > >
> >
> > No problem with this conceptually, the only question I have is which
> > one of these should be stored:
> >  - requested path e.g. 'a_symlink_to_my_favorite_chip'
> >  - canonicalised path e.g. '/dev/gpiochip0'
> >  - chip name e.g. 'gpiochip0'
> >  - chip number e.g. 0
> >
> > In this patch we get the requested path, right?
> >
> 
> Yes, I think we should just use whatever filesystem path was used to
> create the chip as it would be the one allowing the caller to reopen
> the same chip.
> 

So there are instances where those four don't map to the same thing?

Cheers,
Kent.