Hi Paul, > Am 02.02.2022 um 13:06 schrieb Paul Cercueil <paul@xxxxxxxxxxxxxxx>: > > Hi Nikolaus, > >>>> @@ -446,6 +454,9 @@ static int ingenic_drm_plane_atomic_check(struct drm_plane *plane, >>>> if (!crtc) >>>> return 0; >>>> + if (plane == &priv->f0) >>>> + return -EINVAL; >>> This will break JZ4725B -> JZ4770 SoCs, the f0 plane is perfectly usable there. >> Hm. I think it was your request/proposal to add this [1]? > > Because otherwise with your current patchset the f0 plane does not work *on JZ4780*. Not that I am eager to fix that, but... maybe it could be better to fix than having the check and -EINVAL depend on SoC compatible string (or some new flag in soc_info. plane_f0_not_working)? > It does work on older SoCs. > >> What I have forgotten is why the f0 plane should not be usable for jz4780. > > We return an error here to prevent userspace from using the f0 plane until it's effectively working on the JZ4780. Well, what would be not working with that plane if user-space would try to use it? > > Cheers, > -Paul BR and thanks, Nikolaus