Re: [PATCH v3 00/13] Introduce configfs-based interface for gpio-aggregator

From: Koichiro Den
Date: Mon Feb 17 2025 - 07:42:46 EST


On Mon, Feb 17, 2025 at 09:12:07AM GMT, Bartosz Golaszewski wrote:
> On Mon, Feb 17, 2025 at 2:18 AM Koichiro Den <koichiro.den@xxxxxxxxxxxxx> wrote:
> >
> > On Mon, Feb 17, 2025 at 10:07:03AM GMT, Koichiro Den wrote:
> > > On Sun, Feb 16, 2025 at 04:56:59PM GMT, Bartosz Golaszewski wrote:
> > > > On Sun, Feb 16, 2025 at 1:58 PM Koichiro Den <koichiro.den@xxxxxxxxxxxxx> wrote:
> > > > >
> > > > > This patch series introduces a configfs-based interface to gpio-aggregator
> > > > > to address limitations in the existing 'new_device' interface.
> > > > >
> > > > > The existing 'new_device' interface has several limitations:
> > > > >
> > > > > Issue#1. No way to determine when GPIO aggregator creation is complete.
> > > > > Issue#2. No way to retrieve errors when creating a GPIO aggregator.
> > > > > Issue#3. No way to trace a GPIO line of an aggregator back to its
> > > > > corresponding physical device.
> > > > > Issue#4. The 'new_device' echo does not indicate which virtual
> > > > > gpiochip<N> was created.
> > > > > Issue#5. No way to assign names to GPIO lines exported through an
> > > > > aggregator.
> > > > >
> > > > > Although Issue#1 to #3 could technically be resolved easily without
> > > > > configfs, using configfs offers a streamlined, modern, and extensible
> > > > > approach, especially since gpio-sim and gpio-virtuser already utilize
> > > > > configfs.
> > > > >
> > > > > This v3 patch series includes 13 patches:
> > > > >
> > > > > Patch#1-7: Prepare for Patch#8
> > > > > * #1: Prepare for the following patches.
> > > > > * #2: Fix an issue that was spotted during v3 preparation.
> > > > > * #3: Add gpio-pseudo.[ch] to reduce code duplications.
> > > > > * #4: Update gpio-sim to use gpio-pseudo.[ch].
> > > > > * #5: Update gpio-virtuser to use gpio-pseudo.[ch].
> > > > > * #6: Update gpio-aggregator to use gpio-pseudo.[ch].
> > > > > * #7: Add aggr_alloc() to reduce code duplication.
> > > >
> > > > Please don't ram this new functionality into an unrelated series.
> > > > Split it into the gpio-pseudo code, factoring out common parts and
> > > > converting existing drivers, then send the aggregator series saying it
> > > > depends on the former. Otherwise it gets way too complex to review.
> > >
> > > Ok, I'll do so.
> > > Thanks,
> >
> > Should Patch#2 also be split off into another submission?
> >
>
> I'd fold it into the aggregator rework but make it come first in the
> series so that I can pick it up into fixes easily and send it for
> stable.

Ok, thanks for guiding!

Koichiro

>
> Bart