Re: [PATCH libgpiod v5 4/4] dbus: add the D-Bus daemon, command-line client and tests

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Mon, Oct 28, 2024 at 8:35 PM Sverdlin, Alexander
<alexander.sverdlin@xxxxxxxxxxx> wrote:
>
> Hi Bartosz!
>
> On Mon, 2024-10-28 at 20:13 +0100, Bartosz Golaszewski wrote:
> > > Strange, I'd expect from this code to detect pre-existing chips immediately,
> > > but this is not what I observe in practice:
> > >
> > > $ gpiocli info --chip=gpiochip0 | head -n 1
> > > gpiochip0 - 24 lines:
> > > $ gpiocli wait --chip=gpiochip0 --timeout=1
> > > gpiocli wait: wait timed out!
> > >
> > > (without timeout it would wait endlessly)
> > >
> > > This is not expected, right, otherwise it would be counter-intuitive and racy?
> > >
> >
> > gpiochip0 here is the device name. It's dynamic so you cannot use it
> > with gpiocli wait as you cannot know it in advance. You need to use
> > the label of the chip instead.
> >
> > IOW it's a feature. :)
>
> Thanks for the quick reply!
> My bad! Indeed it works as intended with labels!
>
> I think I've found something else, but I didn't have time to look into it deeper:
>
> $ gpiocli info POLA_RS485_2
> gpiochip0   2:  "POLA_RS485_2"          [used,consumer="gpio-manager",managed="request14",output,push-pull]
> $ gpiocli reconfigure --input --both-edges request14
> gpiocli reconfigure: Failed to reconfigure lines: GDBus.Error:io.gpiod1.ReconfigureFailed: failed to reconfigure lines: No such device or address
> $ gpiocli reconfigure --input request14
> $ gpiocli reconfigure --input --both-edges request14
> gpiocli reconfigure: Failed to reconfigure lines: GDBus.Error:io.gpiod1.ReconfigureFailed: failed to reconfigure lines: No such device or address
>
> journal:
> gpio-manager[3043]: failed to reconfigure GPIO lines on request '/io/gpiod1/requests/request14': failed to reconfigure lines: No such device or address
>
> $ gpiocli info POLA_RS485_2
> gpiochip0   2:  "POLA_RS485_2"          [used,consumer="gpio-manager",managed="request14",input]
>
> For me it happens with all GPIOs I've tried, I can reconfigure output to input,
> but not set edge-detection, neither simultaneously, nor after output->input configuration.
> However I don't have any problems to configure edge-detection if I do "gpiocli request".
>
> Just for the case it rings any bells, otherwise I'll look into it in the coming days...
>

Does your driver support edge detection? Does it work with the
first-time request? Does it work with gpiomon without going through
the manager?

Bart