warnings from validate_blend_mode_for_alpha_formats() in next-20260715

warnings from validate_blend_mode_for_alpha_formats() in next-20260715

[Bert Karwatzki]

commit 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed")
introduces validate_blend_mode_for_alpha_formats() which prints warnings for amdpgu as 
amdgpu only set blend_mode_property for planes of type DRM_PLANE_TYPE_OVERLAY. I tried to fix
this by removing he (plane->type == DRM_PLANE_TYPE_OVERLAY) check in amdgpu_dm_plane_init():

	printk(KERN_INFO "%s: plane=%px plane->type=0x%x plane_cap=%px\n", __func__, plane, plane->type, plane_cap);
	if (plane_cap)
		printk(KERN_INFO "%s: per_pixel_alpha =%u\n", __func__, plane_cap->per_pixel_alpha);
	if (plane_cap && plane_cap->per_pixel_alpha) {
		unsigned int blend_caps = BIT(DRM_MODE_BLEND_PIXEL_NONE) |
					  BIT(DRM_MODE_BLEND_PREMULTI) |
					  BIT(DRM_MODE_BLEND_COVERAGE);

		printk(KERN_INFO "%s: creating alpha and blend mode properties for plane %px\n", __func__, plane);
		drm_plane_create_alpha_property(plane);
		drm_plane_create_blend_mode_property(plane, blend_caps);
	}

But this does not completely silence the warnings becuase for planes of type DRM_PLANE_TYPE_CURSOR plane_cap is NULL.
Is this a problem that should be fixed in amdgpu or is should validate_blend_mode_for_alpha_formats() only be called
for planes of certain types?

Bert Karwatzki