ACK/Cmnt: [SRU][K][J, hwe-5.17, oem-5.17, starfive-5.17, allwinner-5.17][PATCH 0/1] Enable CONFIG_GPIO_CDEV_V1

[Emil Renner Berthing]

On Wed, 20 Jul 2022 at 15:11, Tim Gardner <tim.gardner at canonical.com> wrote:
> On 7/20/22 04:40, Emil Renner Berthing wrote:
> > [Impact]
> >
> >   * The libgpiod2 library and gpiod tools shipped in Jammy don't work.
> >
> >   * These tools are meant to replace the old sysfs interface and be
> >     a better and more efficient way to manipulate GPIOs from userspace.
> >     Unfortunately the latest release is still using v1 of the character
> >     device kernel API which is not enabled in Ubuntu kernels.
> >
> >   * This is Kent Gibsons reply on the linux-gpio mailing list:
> >
> > On Tue, Jul 12, 2022 at 09:48:45AM +0200, Alexandre Ghiti wrote:
> >> Hi,
> >>
> >> Ubuntu kernels do not enable GPIO_CDEV_V1 as it is deprecated, but the
> >> libgpiod package that we ship is still based on the latest version
> >> 1.6.3 which does not implement the API v2. So I'd like to update
> >> libgpiod, do you have any recommendations about what branch/sha1 I
> >> should use? Do you plan to make a release that implements the API v2?
> >>
> >
> > Firstly, libgpiod is Bart's library so he is the authority, but this
> > is my understanding...
> >
> > TLDR: You should keep GPIO_CDEV_V1 enabled.
> >
> > v1 is deprecated from a development perspective, so all new feature
> > development will occur on v2, and new applications should target v2.
> > Existing apps targetting v1, be that directly or via libgpiod v1.6.3,
> > will require GPIO_CDEV_V1 until they migrate to v2.
> > The mainline kernel will continue to support v1 while userspace
> > transitions.
> >
> > libgpiod v2 is in active development, and should reach its first release
> > shortly.
> > Note that it is NOT a plugin replacement for v1. It has a different API,
> > for similar reasons to why we had to switch in the kernel, so apps will
> > need to be actively migrated.
> >
> > I wouldn't suggest making any effort to package libgpiod v2 until Bart
> > makes an official release.
> >
> > Cheers,
> > Kent.
> >
> > [Test Plan]
> >
> >   * Run gpioinfo on a machine with exposed GPIOs and check that it lists
> >     the GPIOs and doesn't error with
> >
> >     gpioinfo: error creating line iterator: Invalid argument
> >
> > [Where problems could occur]
> >
> >   * There may be code and scripts that hasn't been tested with a working
> >     libgpiod2/gpiod tools and uncover latent bugs.
> >
> > Emil Renner Berthing (1):
> >    UBUNTU: [Config] Enable CONFIG_GPIO_CDEV_V1
> >
> >   debian.master/config/annotations          | 4 +++-
> >   debian.master/config/config.common.ubuntu | 2 +-
> >   2 files changed, 4 insertions(+), 2 deletions(-)
> >
> Acked-by: Tim Gardner <tim.gardner at canonical.com>
>
> The correct form for a Launchpad URL is 'note<LP: #1953613>'

Ah, I see, thanks. Yeah, the annotations file in kinetic:linux has a
lot of different variations, so I just went with one of the most
common ones.

/Emil
> -----------
> Tim Gardner
> Canonical, Inc