[PATCH 05/10] drm/tests: Add test for drm_framebuffer_cleanup()

[Maira Canal]

Hi Carlos,

On 9/4/23 14:22, Carlos wrote:
> Hi Maíra,
> 
> On 8/26/23 11:06, Maíra Canal wrote:
>> Hi Carlos,
>>
>> On 8/25/23 13:07, Carlos Eduardo Gallo Filho wrote:
>>> Add a single KUnit test case for the drm_framebuffer_cleanup function.
>>>
>>> Signed-off-by: Carlos Eduardo Gallo Filho <gcarlos at disroot.org>
>>> ---
>>>   drivers/gpu/drm/tests/drm_framebuffer_test.c | 49 ++++++++++++++++++++
>>>   1 file changed, 49 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/tests/drm_framebuffer_test.c 
>>> b/drivers/gpu/drm/tests/drm_framebuffer_test.c
>>> index 0e0e8216bbbc..16d9cf4bed88 100644
>>> --- a/drivers/gpu/drm/tests/drm_framebuffer_test.c
>>> +++ b/drivers/gpu/drm/tests/drm_framebuffer_test.c
>>> @@ -370,6 +370,9 @@ static int drm_framebuffer_test_init(struct kunit 
>>> *test)
>>>       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mock);
>>>       dev = &mock->dev;
>>>   +    mutex_init(&dev->mode_config.fb_lock);
>>
>> What about drmm_mutex_init()?
> I took a look into it and as far I understand it would be useful if
> the drm_device was allocated with drmm_kalloc(), sure? As far we

I'm not sure if we can allocate drm_device with drmm_kzalloc(), as we
need a DRM device for drmm_kzalloc(). drmm_kzalloc() is just a
&drm_device managed version of kzalloc().

> are using kunit_kalloc here and the drm_device is automatically
> deallocated when the test finishes, what would be the better by
> using drmm_mutex_init?
> 

Actually, thinking it better now, I think we cannot use
drmm_mutex_init() here, as we are not calling drm_dev_put().

Best Regards,
- Maíra

> It isn't that I don't wanna use it, I just didn't understand how
> exactly it works and how could I use it in that code. Should I
> replace the drm_device allocation to use drmm?
> 
> Thanks,
> Carlos
> 
>> Best Regards,
>> - Maíra
>>
>>> + INIT_LIST_HEAD(&dev->mode_config.fb_list);
>>> +    dev->mode_config.num_fb = 0;
>>>       dev->mode_config.min_width = MIN_WIDTH;
>>>       dev->mode_config.max_width = MAX_WIDTH;
>>>       dev->mode_config.min_height = MIN_HEIGHT;
>>> @@ -380,6 +383,14 @@ static int drm_framebuffer_test_init(struct 
>>> kunit *test)
>>>       return 0;
>>>   }
>>>   +static void drm_framebuffer_test_exit(struct kunit *test)
>>> +{
>>> +    struct drm_mock *mock = test->priv;
>>> +    struct drm_device *dev = &mock->dev;
>>> +
>>> +    mutex_destroy(&dev->mode_config.fb_lock);
>>> +}
>>> +
>>>   static void drm_test_framebuffer_create(struct kunit *test)
>>>   {
>>>       const struct drm_framebuffer_test *params = test->param_value;
>>> @@ -483,7 +494,44 @@ static void check_src_coords_test_to_desc(const 
>>> struct check_src_coords_case *t,
>>>   KUNIT_ARRAY_PARAM(check_src_coords, check_src_coords_cases,
>>>             check_src_coords_test_to_desc);
>>>   +static void drm_test_framebuffer_cleanup(struct kunit *test)
>>> +{
>>> +    struct drm_mock *mock = test->priv;
>>> +    struct drm_device *dev = &mock->dev;
>>> +    struct list_head *fb_list = &dev->mode_config.fb_list;
>>> +    struct drm_framebuffer fb1 = { .dev = dev };
>>> +    struct drm_framebuffer fb2 = { .dev = dev };
>>> +
>>> +    /* This must result on [fb_list] -> fb1 -> fb2 */
>>> +    list_add_tail(&fb1.head, fb_list);
>>> +    list_add_tail(&fb2.head, fb_list);
>>> +    dev->mode_config.num_fb = 2;
>>> +
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb_list->prev, &fb2.head);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb_list->next, &fb1.head);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb1.head.prev, fb_list);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb1.head.next, &fb2.head);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb2.head.prev, &fb1.head);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb2.head.next, fb_list);
>>> +
>>> +    drm_framebuffer_cleanup(&fb1);
>>> +
>>> +    /* Now [fb_list] -> fb2 */
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb_list->prev, &fb2.head);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb_list->next, &fb2.head);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb2.head.prev, fb_list);
>>> +    KUNIT_ASSERT_PTR_EQ(test, fb2.head.next, fb_list);
>>> +    KUNIT_ASSERT_EQ(test, dev->mode_config.num_fb, 1);
>>> +
>>> +    drm_framebuffer_cleanup(&fb2);
>>> +
>>> +    /* Now fb_list is empty */
>>> +    KUNIT_ASSERT_TRUE(test, list_empty(fb_list));
>>> +    KUNIT_ASSERT_EQ(test, dev->mode_config.num_fb, 0);
>>> +}
>>> +
>>>   static struct kunit_case drm_framebuffer_tests[] = {
>>> +    KUNIT_CASE(drm_test_framebuffer_cleanup),
>>> KUNIT_CASE(drm_test_framebuffer_modifiers_not_supported),
>>>       KUNIT_CASE_PARAM(drm_test_framebuffer_check_src_coords, 
>>> check_src_coords_gen_params),
>>>       KUNIT_CASE_PARAM(drm_test_framebuffer_create, 
>>> drm_framebuffer_create_gen_params),
>>> @@ -493,6 +541,7 @@ static struct kunit_case drm_framebuffer_tests[] = {
>>>   static struct kunit_suite drm_framebuffer_test_suite = {
>>>       .name = "drm_framebuffer",
>>>       .init = drm_framebuffer_test_init,
>>> +    .exit = drm_framebuffer_test_exit,
>>>       .test_cases = drm_framebuffer_tests,
>>>   };