Messages in this thread | | | Date | Fri, 24 Mar 2023 08:51:53 +0200 | From | Matti Vaittinen <> | Subject | Re: [PATCH v5 1/8] drivers: kunit: Generic helpers for test device creation |
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On 3/24/23 08:34, David Gow wrote: > On Fri, 24 Mar 2023 at 14:11, Matti Vaittinen <mazziesaccount@gmail.com> wrote: >> >> On 3/23/23 18:36, Maxime Ripard wrote: >>> On Thu, Mar 23, 2023 at 03:02:03PM +0200, Matti Vaittinen wrote: >>>> On 3/23/23 14:29, Maxime Ripard wrote: >>>>> On Thu, Mar 23, 2023 at 02:16:52PM +0200, Matti Vaittinen wrote:
>> Ok. Fair enough. Besides, if the root-device was sufficient - then I >> would actually not see the need for a helper. People could in that case >> directly use the root_device_register(). So, if helpers are provided >> they should be backed up by a device with a bus then. > > I think there is _some_ value in helpers even without a bus, but it's > much more limited: > - It's less confusing if KUnit test devices are using kunit labelled > structs and functions. > - Helpers could use KUnit's resource management API to ensure any > device created is properly unregistered and removed when the test > exits (particularly if it exits early due to, e.g., an assertion).
Ah. That's true. Being able to abort the test on error w/o being forced to do a clean-up dance for the dummy device would be convenient.
> I've played around implementing those with a proper struct > kunit_device and the automatic cleanup on test failure, and thus far > it -- like root_device_register -- works for all of the tests except > the drm-test-managed one. > > So if we really wanted to, we could use KUnit-specific helpers for > just those tests which currently work with root_device_register(), but > if we're going to try to implement a KUnit bus -- which I think is at > least worth investigating -- I'd rather not either hold up otherwise > good tests on helper development, or rush a helper out only to have to > change it a lot when we see exactly what the bus implementation would > look like.
It's easy for me to agree.
>> As I said, in my very specific IIO related test the test device does not >> need a bus. Hence I'll drop the 'generic helpers' from this series. >> > > 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.
Yours, -- Matti
-- Matti Vaittinen Linux kernel developer at ROHM Semiconductors Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
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