Re: [PATCH v5 2/3] tests/qtest: Add STM32L4x5 EXTI QTest testcase

[Philippe Mathieu-Daudé]

(+Mark & Eduardo)

On 4/1/24 14:37, inesvarhol wrote:
> Le jeudi 4 janvier 2024 à 14:05, Philippe Mathieu-Daudé <philmd@linaro.org> a 
> écrit :
>
> Hello,
>
> > > +static void test_edge_selector(void)
> > > +{
> > > + enable_nvic_irq(EXTI0_IRQ);
> > > +
> > > + / Configure EXTI line 0 irq on rising edge */
> > > + qtest_set_irq_in(global_qtest, "/machine/unattached/device[0]/exti",
> >
> >
> > Markus, this qtest use seems to expect some stability in QOM path...
> >
> > Inès, Arnaud, having the SoC unattached is dubious, it belongs to
> > the machine.
>
> Noted, we will fix that.
> Should we be concerned about the "stability in QOM path" ?

Don't worry about this Inès, I wanted to raise Markus attention on this.

You showed a legit use of stable QOM path, and Markus told me recently
there is no contract for QOM paths (it shouldn't be considered as a
stable API). IIRC Markus explanation, "/unattached" container was
added as a temporary hack to allow migrating QDev objects to QOM (see
around commit da57febfed "qdev: give all devices a canonical path",
11 years ago).

I agree anything under "/unattached" can be expected to be stable
(but we need a community consensus). Then the big question remaining
is "can any qom-path out of /unattached be considered stable?"

Regards,

Phil.