Re: [libgpiod v2.0][PATCH] core: extend config objects

[Kent Gibson <warthog618@xxxxxxxxx>]

On Thu, Aug 12, 2021 at 04:43:46PM +0200, Bartosz Golaszewski wrote:
> On Thu, Aug 12, 2021 at 4:23 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
> >
> > On Thu, Aug 12, 2021 at 02:51:02PM +0200, Bartosz Golaszewski wrote:
> > > On Thu, Aug 12, 2021 at 12:29 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
> > > >
> > >
> >
> > <snip>
> >
> > > >
> > > > Sure, it's a trade-off, but the alternative is requiring a 2-3k block
> > > > even for a one line request, which seems a wee bit excessive.
> > > >
> > >
> > > As you said - it's on the heap, so who cares. But this is also an
> > > internal structure and so we can use bit fields. That should reduce
> > > the memory footprint significantly as we now don't require more than 3
> > > bits for any given enum. That would leave us with the debounce period
> > > and offset as full size variables.
> > >
> >
> > Rather than introducing a new collection of enums and bitfields, why not
> > just store the v2 flags for the line?
> >
> 
> Why a new collection of enums? It wouldn't change anything, we'd just
> make sure in the setters we never overflow.
> 

Yeah, my bad - you already have the enums.

> I would prefer to limit the use of kernel symbols (and types!) to the
> minimum for clarity.
> 

OK, but you need to map the libgpiod config to kernel flags at some
point...
And this is all internal to line-config.c...

Cheers,
Kent.