Re: [PATCH v5 1/8] drivers: kunit: Generic helpers for test device creation

[Matti Vaittinen]

On 3/24/23 12:05, Matti Vaittinen wrote:
> On 3/24/23 11:52, David Gow wrote:
> > On Fri, 24 Mar 2023 at 14:51, Matti Vaittinen 
> > <mazziesaccount@xxxxxxxxx> wrote:
> > > On 3/24/23 08:34, David Gow wrote:
> > > > On Fri, 24 Mar 2023 at 14:11, Matti Vaittinen 
> > > > <mazziesaccount@xxxxxxxxx> wrote:
>
> > > > I think that sounds like a good strategy for now, and we can work on a
> > > > set of 'generic helpers' which have an associated bus and struct
> > > > kunit_device in the meantime. If we can continue to use
> > > > root_device_register until those are ready, that'd be very convenient.
> > >
> > > Would it be a tiny bit more acceptable if we did add a very simple:
> > >
> > > #define kunit_root_device_register(name) root_device_register(name)
> > > #define kunit_root_device_unregister(dev) root_device_unregister(dev)
> > >
> > > to include/kunit/device.h (or somesuch)
> > >
> > > This should help us later to at least spot the places where
> > > root_device_[un]register() is abused and (potentially mass-)covert them
> > > to use the proper helpers when they're available.
> >
> > Great idea.
> >
> > The code I've been playing with has the following in 
> > include/kunit/device.h:
> >
> > /* Register a new device against a KUnit test. */
> > struct device *kunit_device_register(struct kunit *test, const char 
> > *name);
> > /* Unregister a device created by kunit_device_register() early (i.e.,
> > before test cleanup). */
> > void kunit_device_unregister(struct kunit *test, struct device *dev);
> >
> > If we used the same names, and just forwarded them to
> > root_device_register() and root_device_unregister() for now
> > (discarding the struct kunit pointer), then I expect we could just
> > swap out the implementation to gain the extra functionality.

There's one thing though. If the goal is to do a direct replacement and 
if automatic device deletion upon test completion / test abort is 
planned - then it should be there also for these initial wrappers.

If these wrappers don't yet include the automatic device clean-up - then 
it probably makes more sense to just do the kunit_root_device_* defines 
because the tests are likely to need removing the explicit device 
clean-ups when proper APIs are finished.

Yours,
	-- Matti

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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