On Thu, Mar 2, 2023 at 2:14 AM David Gow davidgow@google.com wrote:
On Thu, 2 Mar 2023 at 09:38, Stephen Boyd sboyd@kernel.org wrote:
This patch series adds unit tests for the clk fixed rate basic type and the clk registration functions that use struct clk_parent_data. To get there, we add support for loading a DTB into the UML kernel that's running the unit tests along with probing platform drivers to bind to device nodes specified in DT.
With this series, we're able to exercise some of the code in the common clk framework that uses devicetree lookups to find parents and the fixed rate clk code that scans devicetree directly and creates clks. Please review.
Thanks Stephen -- this is really neat!
This works well here, and I love all of the tests for the KUnit/device-tree integration as well.
I'm still looking through the details of it (alas, I've mostly lived in x86-land, so my device-tree knowledge is, uh, spotty to say the least), but apart from possibly renaming some things or similarly minor tweaks, I've not got any real suggestions thus far.
I do wonder whether we'll want, on the KUnit side, to have some way of supporting KUnit device trees on non-UML architecctures (e.g., if we need to test something architecture-specific, or on a big-endian platform, etc), but I think that's a question for the future, rather than something that affects this series.
I'll say that's a requirement. We should be able to structure the tests to not interfere with the running system's DT. The DT unittest does that.
As a side topic, Is anyone looking at getting UML to work on arm64? It's surprising how much x86 stuff there is which is I guess one reason it hasn't happened.
Similarly, I wonder if there's something we could do with device tree overlays, in order to make it possible for tests to swap nodes in and out for testing.
Yes, that's how the DT unittest works. But it is pretty much one big overlay (ignoring the overlay tests). It could probably be more modular where it is apply overlay, test, remove overlay, repeat.
Rob