Re: [PATCH 2/5] drm/tests: shmem: Add clean-up action to unpin pages

[Boris Brezillon <boris.brezillon@collabora.com>]

On Fri, 12 Dec 2025 17:00:33 +0100
Thomas Zimmermann <tzimmermann@suse.de> wrote:

> Automatically unpin pages on cleanup. The test currently fails with
> the error
> 
> [   58.246263] drm-kunit-mock-device drm_gem_shmem_test_get_sg_table.drm-kunit-mock-device: [drm] drm_WARN_ON(refcount_read(&shmem->pages_pin_count))
> 
> while cleaning up the GEM object. The pin count has to be zero at this
> point.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: d586b535f144 ("drm/shmem-helper: Add and use pages_pin_count")
> Cc: dri-devel@lists.freedesktop.org
> Cc: <stable@vger.kernel.org> # v6.16+

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/gpu/drm/tests/drm_gem_shmem_test.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> index 872881ec9c30..1d50bab51ef3 100644
> --- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> +++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> @@ -34,6 +34,9 @@ KUNIT_DEFINE_ACTION_WRAPPER(sg_free_table_wrapper, sg_free_table,
>  KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_free_wrapper, drm_gem_shmem_free,
>  			    struct drm_gem_shmem_object *);
>  
> +KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_unpin_wrapper, drm_gem_shmem_unpin,
> +			    struct drm_gem_shmem_object *);
> +
>  /*
>   * Test creating a shmem GEM object backed by shmem buffer. The test
>   * case succeeds if the GEM object is successfully allocated with the
> @@ -212,6 +215,9 @@ static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
>  	ret = drm_gem_shmem_pin(shmem);
>  	KUNIT_ASSERT_EQ(test, ret, 0);
>  
> +	ret = kunit_add_action_or_reset(test, drm_gem_shmem_unpin_wrapper, shmem);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
>  	sgt = drm_gem_shmem_get_sg_table(shmem);
>  	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
>  	KUNIT_EXPECT_NULL(test, shmem->sgt);