On 5/19/25 11:42 AM, Maxime Ripard wrote:
> Hi,
>
> On Fri, Apr 25, 2025 at 01:27:14PM +0300, Cristian Ciocaltea wrote:
>> Provide a test to verify that if both driver and screen support RGB and
>> YUV420 formats, drm_atomic_helper_connector_hdmi_check() cannot succeed
>> when trying to set a mode unsupported by the display.
>>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocal...@collabora.com>
>> ---
>> drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 66
>> ++++++++++++++++++++++
>> 1 file changed, 66 insertions(+)
>>
>> 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
>> d79084cfb516b69c4244098c0767d604ad02f2c3..6337a1c52b86810c638f446c4995e7ee63dbc084
>> 100644
>> --- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
>> +++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
>> @@ -1622,6 +1622,71 @@ static void
>> drm_test_check_driver_unsupported_fallback_yuv420(struct kunit *test
>> drm_modeset_acquire_fini(&ctx);
>> }
>>
>> +/*
>> + * Test that if a driver and screen supports RGB and YUV420 formats, but the
>> + * chosen mode cannot be supported by the screen, we end up with
>> unsuccessful
>> + * fallback attempts.
>> + */
>> +static void drm_test_check_display_unsupported_fallback_rgb_yuv420(struct
>> kunit *test)
>> +{
>> + struct drm_atomic_helper_connector_hdmi_priv *priv;
>> + struct drm_modeset_acquire_ctx ctx;
>> + struct drm_crtc_state *crtc_state;
>> + struct drm_atomic_state *state;
>> + struct drm_display_info *info;
>> + struct drm_display_mode *preferred, *unsupported_mode;
>> + struct drm_connector *conn;
>> + struct drm_device *drm;
>> + struct drm_crtc *crtc;
>> + int ret;
>> +
>> + priv = drm_kunit_helper_connector_hdmi_init_with_edid_funcs(test,
>> + BIT(HDMI_COLORSPACE_RGB) |
>> + BIT(HDMI_COLORSPACE_YUV420),
>> + 10,
>> + &dummy_connector_hdmi_funcs,
>> + test_edid_hdmi_4k_rgb_yuv420_dc_max_340mhz);
>> + KUNIT_ASSERT_NOT_NULL(test, priv);
>> +
>> + drm = &priv->drm;
>> + crtc = priv->crtc;
>> + conn = &priv->connector;
>> + info = &conn->display_info;
>> + KUNIT_ASSERT_TRUE(test, info->is_hdmi);
>> + KUNIT_ASSERT_TRUE(test, conn->ycbcr_420_allowed);
>> +
>> + preferred = find_preferred_mode(conn);
>> + KUNIT_ASSERT_NOT_NULL(test, preferred);
>> +
>> + unsupported_mode = drm_kunit_display_mode_from_cea_vic(test, drm, 96);
>> + KUNIT_ASSERT_NOT_NULL(test, unsupported_mode);
>
> I'm not sure what this one is supposed to test. If the mode is
> unsupported by the screen, it will be for both YUV and RGB, right? So
> what are we testing here?
That would be the case suggested at [1]:
"We still need to do the same with a driver that supports both, but the
monitor doesn't."
Should we drop it?
[1] https://lore.kernel.org/all/20250410-singing-scarlet-carp-d136f9@houat/
