Re: [PATCH v2 5/7] drm/tests: hdmi: Add macros to simplify EDID setup

[Cristian Ciocaltea <cristian.ciocaltea@collabora.com>]

On 3/11/25 6:12 PM, Maxime Ripard wrote:
> On Tue, Mar 11, 2025 at 12:57:37PM +0200, Cristian Ciocaltea wrote:
>> Introduce a few macros to facilitate setting custom (i.e. non-default)
>> EDID data during connector initialization.
>>
>> This helps reducing boilerplate code while also drops some redundant
>> calls to set_connector_edid().
>>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> ---
>>  drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 245 ++++++++-------------
>>  1 file changed, 93 insertions(+), 152 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
>> index e97efd3af9ed18e6cf8ee66b4923dfc805b34e19..a3f7f3ce31c73335c2c2643bdc5395b6ceb6f071 100644
>> --- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
>> +++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
>> @@ -183,10 +183,12 @@ static const struct drm_connector_funcs dummy_connector_funcs = {
>>  
>>  static
>>  struct drm_atomic_helper_connector_hdmi_priv *
>> -drm_kunit_helper_connector_hdmi_init_funcs(struct kunit *test,
>> -					   unsigned int formats,
>> -					   unsigned int max_bpc,
>> -					   const struct drm_connector_hdmi_funcs *hdmi_funcs)
>> +connector_hdmi_init_funcs_set_edid(struct kunit *test,
>> +				   unsigned int formats,
>> +				   unsigned int max_bpc,
>> +				   const struct drm_connector_hdmi_funcs *hdmi_funcs,
>> +				   const char *edid_data,
>> +				   size_t edid_len)
>>  {
>>  	struct drm_atomic_helper_connector_hdmi_priv *priv;
>>  	struct drm_connector *conn;
>> @@ -240,30 +242,27 @@ drm_kunit_helper_connector_hdmi_init_funcs(struct kunit *test,
>>  
>>  	drm_mode_config_reset(drm);
>>  
>> +	if (edid_data && edid_len) {
>> +		ret = set_connector_edid(test, &priv->connector, edid_data, edid_len);
>> +		KUNIT_ASSERT_GT(test, ret, 0);
>> +	}
>> +
>>  	return priv;
>>  }
>>  
>> -static
>> -struct drm_atomic_helper_connector_hdmi_priv *
>> -drm_kunit_helper_connector_hdmi_init(struct kunit *test,
>> -				     unsigned int formats,
>> -				     unsigned int max_bpc)
>> -{
>> -	struct drm_atomic_helper_connector_hdmi_priv *priv;
>> -	int ret;
>> +#define drm_kunit_helper_connector_hdmi_init_funcs_set_edid(test, formats, max_bpc, funcs, edid) \
>> +	connector_hdmi_init_funcs_set_edid(test, formats, max_bpc, funcs, edid, ARRAY_SIZE(edid))
>>  
>> -	priv = drm_kunit_helper_connector_hdmi_init_funcs(test,
>> -							  formats, max_bpc,
>> -							  &dummy_connector_hdmi_funcs);
>> -	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
>> +#define drm_kunit_helper_connector_hdmi_init_funcs(test, formats, max_bpc, funcs)		\
>> +	connector_hdmi_init_funcs_set_edid(test, formats, max_bpc, funcs, NULL, 0)
>>  
>> -	ret = set_connector_edid(test, &priv->connector,
>> -				 test_edid_hdmi_1080p_rgb_max_200mhz,
>> -				 ARRAY_SIZE(test_edid_hdmi_1080p_rgb_max_200mhz));
>> -	KUNIT_ASSERT_GT(test, ret, 0);
>> +#define drm_kunit_helper_connector_hdmi_init_set_edid(test, formats, max_bpc, edid)		\
>> +	drm_kunit_helper_connector_hdmi_init_funcs_set_edid(test, formats, max_bpc,		\
>> +							    &dummy_connector_hdmi_funcs, edid)
>>  
>> -	return priv;
>> -}
>> +#define drm_kunit_helper_connector_hdmi_init(test, formats, max_bpc)				\
>> +	drm_kunit_helper_connector_hdmi_init_set_edid(test, formats, max_bpc,			\
>> +						      test_edid_hdmi_1080p_rgb_max_200mhz)
> 
> I'd really prefer to have functions to macros here. They are easier to
> read, extend, and don't have any particular drawbacks.

Yeah, the main reason I opted for macros was to allow dropping
ARRAY_SIZE(edid) from the caller side, hence making the API as simple as
possible.

> I also don't think we need that many, looking at the tests:
> 
>   - We need drm_kunit_helper_connector_hdmi_init() to setup a connector
>     with test_edid_hdmi_1080p_rgb_max_200mhz and
>     dummy_connector_hdmi_funcs()

Correct.

>   - We need to create a
>     drm_kunit_helper_connector_hdmi_init_with_edid_funcs() to pass both
>     the funcs and edid pointers

That's drm_kunit_helper_connector_hdmi_init_funcs_set_edid(), but I can
rename it if you prefer - I've just tried to keep the name length under
control, as there are already some indentation challenges when calling
the helpers.

Currently it's only used to implement
drm_kunit_helper_connector_hdmi_init_set_edid() by passing
&dummy_connector_hdmi_funcs, but there are a few test cases that can
benefit of it and help extend the cleanup - will do for v3.

drm_kunit_helper_connector_hdmi_init_set_edid() should also stay as it's
already being used to drop boilerplate code from a lot of places.

> And that's it, right?

There's also drm_kunit_helper_connector_hdmi_init_funcs() which has been
used for a few times, but it can be further optimized out via
drm_kunit_helper_connector_hdmi_init_funcs_set_edid(), so I'll drop it.

That means we could end up with just the following:

- drm_kunit_helper_connector_hdmi_init()
- drm_kunit_helper_connector_hdmi_init_set_edid()
- drm_kunit_helper_connector_hdmi_init_funcs_set_edid()

>>  /*
>>   * Test that if we change the RGB quantization property to a different
>> @@ -771,19 +770,15 @@ static void drm_test_check_output_bpc_crtc_mode_changed(struct kunit *test)
>>  	struct drm_crtc *crtc;
>>  	int ret;
>>  
>> -	priv = drm_kunit_helper_connector_hdmi_init(test,
>> -						    BIT(HDMI_COLORSPACE_RGB),
>> -						    10);
>> +	priv = drm_kunit_helper_connector_hdmi_init_set_edid(test,
>> +				BIT(HDMI_COLORSPACE_RGB),
>> +				10,
>> +				test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz);
> 
> I think that convertion should be part of another patch.

Ack, will move all conversions to a dedicated patch.

Thanks,
Cristian