kernel/linux.git/drivers/of/of_kunit_helpers.c, branch linux-7.1.y

of: Skip devicetree kunit tests when RISCV+ACPI doesn't populate root node

2025-11-27T01:46:23+00:00

Starting with commit 69a8b62a7aa1 ("riscv: acpi: avoid errors caused by probing DT devices when ACPI is used"), riscv images no longer populate devicetree if ACPI is enabled. This causes unit tests to fail which require the root node to be set. # Subtest: of_dtb # module: of_test 1..2 # of_dtb_root_node_found_by_path: EXPECTATION FAILED at drivers/of/of_test.c:21 Expected np is not null, but is # of_dtb_root_node_found_by_path: pass:0 fail:1 skip:0 total:1 not ok 1 of_dtb_root_node_found_by_path # of_dtb_root_node_populates_of_root: EXPECTATION FAILED at drivers/of/of_test.c:31 Expected of_root is not null, but is # of_dtb_root_node_populates_of_root: pass:0 fail:1 skip:0 total:1 not ok 2 of_dtb_root_node_populates_of_root Skip those tests for RISCV if the root node is not populated. Fixes: 69a8b62a7aa1 ("riscv: acpi: avoid errors caused by probing DT devices when ACPI is used") Cc: Han Gao Cc: Paul Walmsley Signed-off-by: Guenter Roeck Reviewed-by: Paul Walmsley # arch/riscv Link: https://patch.msgid.link/20251023160415.705294-1-linux@roeck-us.net Signed-off-by: Rob Herring (Arm)

of: Skip kunit tests when arm64+ACPI doesn't populate root node

2024-10-10T17:43:01+00:00

A root node is required to apply DT overlays. A root node is usually present after commit 7b937cc243e5 ("of: Create of_root if no dtb provided by firmware"), except for on arm64 systems booted with ACPI tables. In that case, the root node is intentionally not populated because it would "allow DT devices to be instantiated atop an ACPI base system"[1]. Introduce an OF function that skips the kunit test if the root node isn't populated. Limit the test to when both CONFIG_ARM64 and CONFIG_ACPI are set, because otherwise the lack of a root node is a bug. Make the function private and take a kunit test parameter so that it can't be abused to test for the presence of the root node in non-test code. Use this function to skip tests that require the root node. Currently that's the DT tests and any tests that apply overlays. Reported-by: Guenter Roeck Closes: https://lore.kernel.org/r/6cd337fb-38f0-41cb-b942-5844b84433db@roeck-us.net Link: https://lore.kernel.org/r/Zd4dQpHO7em1ji67@FVFF77S0Q05N.cambridge.arm.com [1] Fixes: 893ecc6d2d61 ("of: Add KUnit test to confirm DTB is loaded") Signed-off-by: Stephen Boyd Tested-by: Guenter Roeck Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20241009204133.1169931-1-sboyd@kernel.org Signed-off-by: Rob Herring (Arm)

of: Add test managed wrappers for of_overlay_apply()/of_node_put()

2024-07-29T22:33:12+00:00

Add test managed wrappers for of_overlay_apply() that automatically removes the overlay when the test is finished. This API is intended for use by KUnit tests that test code which relies on 'struct device_node's and of_*() APIs. KUnit tests will call of_overlay_apply_kunit() to load an overlay that's been built into the kernel image. When the test is complete, the overlay will be removed. This has a few benefits: 1) It keeps the tests hermetic because the overlay is removed when the test is complete. Tests won't even be aware that an overlay was loaded in another test. 2) The overlay code can live right next to the unit test that loads it. The overlay and the unit test can be compiled into one kernel module if desired. 3) We can test different device tree configurations by loading different overlays. The overlays can be written for a specific test, and there can be many of them loaded per-test without needing to jam all possible combinations into one DTB. 4) It also allows KUnit to test device tree dependent code on any architecture, not just UML. This allows KUnit tests to test architecture specific device tree code. There are some potential pitfalls though. Test authors need to be careful to not overwrite properties in the live tree. The easiest way to do this is to add and remove nodes with a 'kunit-' prefix, almost guaranteeing that the same node won't be present in the tree loaded at boot. Suggested-by: Rob Herring Cc: Rob Herring Cc: Saravana Kannan Reviewed-by: Rob Herring (Arm) Reviewed-by: David Gow Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20240718210513.3801024-3-sboyd@kernel.org