On Thu, Mar 23, 2023 at 12:01:15PM +0200, Matti Vaittinen wrote:
> On 3/23/23 10:58, Greg Kroah-Hartman wrote:
> > On Thu, Mar 23, 2023 at 07:17:40AM +0000, Vaittinen, Matti wrote:
> > > On 3/22/23 20:57, Greg Kroah-Hartman wrote:
> > > > On Wed, Mar 22, 2023 at 03:48:00PM +0200, Matti Vaittinen wrote:
> > > > > Hi Greg,
> > > > >
> > > > > Thanks for looking at this.
> > > > >
> > > > > On 3/22/23 14:07, Greg Kroah-Hartman wrote:
> > > > > > On Wed, Mar 22, 2023 at 11:05:55AM +0200, Matti Vaittinen wrote:
>
> > > > > The biggest thing for me is that I don't like the idea of creating own 'test
> > > > > device' in <add subsystem here> while we already have some in DRM (or
> > > > > others). Thus, I do see value in adding generic helpers for supporting
> > > > > running KUnit tests on devm_* APIs. Hence it'd be good to have _some_
> > > > > support for it.
> > > >
> > > > I agree, let's use a virtual device and a virtual bus (you can use the
> > > > auxbus code for this as that's all there for this type of thing)
> > >
> > > Hm. The auxiliary_devices require parent. What would be the best way to
> > > deal with that in KUnit tests?
> >
> > If you use NULL as the parent, it goes into the root.
>
> As far as I read this is not the case with auxiliary devices. Judging the
> docs they were intended to be representing some part of a (parent) device. I
> see the auxiliary_device_init() has explicit check for parent being
> populated:
>
> int auxiliary_device_init(struct auxiliary_device *auxdev)
> {
> struct device *dev = &auxdev->dev;
>
> if (!dev->parent) {
> pr_err("auxiliary_device has a NULL dev->parent\n");
> return -EINVAL;
> }
Yes as it wants to "split" a device up into smaller devices. So make a
real device that it can hang off of.
> As I wrote in another mail, I thought of using a root_device for this IIO
> test as was suggested by David. To tell the truth, implementing a kunit bus
> device is starting to feel a bit overwhelming... I started just adding a
> driver for a light sensor, ended up adding a helper for IIO gain-time-scale
> conversions and I am slightly reluctant to going the extra-extra mile of
> adding some UT infrastructure in the context of this driver work...
I think it is worth it as the driver core has no tests. So it obviously
must be correct, right? :)
thanks,
greg k-h
