Quoting Guenter Roeck (2024-10-08 16:27:37)
On 10/8/24 16:12, Stephen Boyd wrote:
The best I can come up with then is to test for a NULL of_root when CONFIG_ARM64 and CONFIG_ACPI are enabled, because the tests intentionally don't work when both those configs are enabled and the 'of_root' isn't populated. In all other cases the 'of_root' missing is a bug. I'll probably make this into some sort of kunit helper function in of_private.h and send it to DT maintainers.
Sounds good. Thanks a lot for tracking this down.
That makes me wonder though why only arm64 has that restriction. Both riscv and loongarch have ACPI enabled in their defconfig files but call unflatten_device_tree() unconditionally.
Oh well ...
Some of the reason is described in the thread I linked earlier. In particular, this email from Mark[1]. There's also more comments from Mark on an earlier patchset[2]. Maybe arm64 will allow it later, and then we'll be able to revert this skip patch.
[1] https://lore.kernel.org/all/Zd4dQpHO7em1ji67@FVFF77S0Q05N.cambridge.arm.com/ [2] https://lore.kernel.org/all/ZaZtbU9hre3YhZam@FVFF77S0Q05N/