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

[Maira Canal <mairacanal@xxxxxxxxxx>]

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@xxxxxxxxxxx>
> > > ---
> > >   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,
> > >   };