Quoting Frank Rowand (2023-03-04 07:04:48) > On 3/2/23 13:27, Stephen Boyd wrote: > > > > But perhaps this design is too much of an end-to-end test and not a unit > > test? In the spirit of unit testing we shouldn't care about how the node > > is added to the live devicetree, just that there is a devicetree at all. > > > > Supporting overlays to more easily test combinations sounds like a good > > idea. Probably some kunit_*() prefixed functions could be used to > > In an imaginary world where overlay support was completed, then _maybe_. > > To me, the most important environment to test is where the devictree > data is populated in early boot from an FDT. This is the environment > that drivers currently exist in. > > Populating devicetree data via an overlay adds in the functioning of the > overlay apply code (and how the rules behind that functioning may differ > from devicetree data populated in early boot from an FDT).
For the purposes of clk unit tests I don't care where the devicetree nodes come from. All I care about is that they're rooted in the live devicetree for the system and that they have platform devices attached to them. The clk unit tests will assert that the overlay has been applied and that should be sufficient to make sure the tests has satisfied pre-conditions. If these were end-to-end tests then I would agree that making the nodes be loaded during early boot from an FDT would be the right approach. That would test the integration of early DTB loading and code that runs on the FDT. These aren't integration tests though, so when the nodes are created and unflattened doesn't matter. I'll introduce various unit tests around the kunit specific overlay application API so that I know it makes platform devices and they have device nodes attached to them. And those same tests should be able to confirm that devices are destroyed when the overlay is removed. _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um
