Re: [PATCH v2 0/3] drivers: base: Add tests showing devm handling inconsistencies

[David Gow]

On Wed, 28 Jun 2023 at 17:50, Maxime Ripard <mripard@xxxxxxxxxx> wrote:
>
> 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>
> ---

Whoops, sorry. This managed to hide in my inbox. I think it looks
good, and am happy for you to add by SoB to the patch.

I've sent out reviews to the others with some small nitpicky things.

Thanks a bunch,
-- David

> 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>
>

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