Hi, This follows the discussion here: https://lore.kernel.org/linux-kselftest/20230324123157.bbwvfq4gsxnlnfwb@houat/ This shows a couple of inconsistencies with regard to how device-managed resources are cleaned up. Basically, devm resources will only be cleaned up if the device is attached to a bus and bound to a driver. Failing any of these cases, a call to device_unregister will not end up in the devm resources being released. We had to work around it in DRM to provide helpers to create a device for kunit tests, but the current discussion around creating similar, generic, helpers for kunit resumed interest in fixing this. This can be tested using the command: ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/base/test/ I added the fix David suggested back in that discussion which does fix the tests. The SoB is missing, since David didn't provide it back then. Let me know what you think, Maxime Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> --- Changes in v2: - Use an init function - Document the tests - Add a fix for the bugs - Link to v1: https://lore.kernel.org/r/20230329-kunit-devm-inconsistencies-test-v1-0-c33127048375@xxxxxxxxxx --- David Gow (1): drivers: base: Free devm resources when unregistering a device Maxime Ripard (2): drivers: base: Add basic devm tests for root devices drivers: base: Add basic devm tests for platform devices drivers/base/core.c | 11 ++ drivers/base/test/.kunitconfig | 2 + drivers/base/test/Kconfig | 4 + drivers/base/test/Makefile | 3 + drivers/base/test/platform-device-test.c | 220 +++++++++++++++++++++++++++++++ drivers/base/test/root-device-test.c | 108 +++++++++++++++ 6 files changed, 348 insertions(+) --- base-commit: 53cdf865f90ba922a854c65ed05b519f9d728424 change-id: 20230329-kunit-devm-inconsistencies-test-5e5a7d01e60d Best regards, -- Maxime Ripard <mripard@xxxxxxxxxx>
