Re: [PATCH v4] drm/test: add a test suite for GEM objects backed by shmem

[Marco Pagani <marpagan@redhat.com>]

On 2023-11-24 09:49, Maxime Ripard wrote:
> Hi,
> 
> On Thu, Nov 23, 2023 at 11:01:46AM +0100, Marco Pagani wrote:
>> +static int drm_gem_shmem_test_init(struct kunit *test)
>> +{
>> +	struct device *dev;
>> +	struct fake_dev {
>> +		struct drm_device drm_dev;
>> +	} *fdev;
>> +
> 
> [...]
> 
>> +
>> +	/*
>> +	 * The DRM core will automatically initialize the GEM core and create
>> +	 * a DRM Memory Manager object which provides an address space pool
>> +	 * for GEM objects allocation.
>> +	 */
>> +	fdev = drm_kunit_helper_alloc_drm_device(test, dev, struct fake_dev,
>> +						 drm_dev, DRIVER_GEM);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fdev);
> 
> Sorry I missed it earlier, but you don't need the intermediate structure
> if you use
> 
> struct drm_device *drm;
> 
> drm = __drm_kunit_helper_alloc_drm_device(test, dev, sizeof(*drm), 0, DRIVER_GEM);
> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, drm);
>

I prefer to use drm_kunit_helper_alloc_drm_device() with the intermediate
structure. It makes the code clearer, in my opinion. Initially, when
developing the suite, I was using __drm_kunit_helper_alloc_drm_device()
as most test suites do, but I feel the list of arguments including
"sizeof(*drm), 0," is less straightforward to understand.

Thanks,
Marco