On Tue, May 26, 2020 at 6:31 AM Yogish Kulkarni <yogishkulka...@gmail.com> wrote: > > Hi, > > Is it possible to dynamically change enumeration list of DRM enumeration > property ? Motivation behind this question is to understand whether it is > possible to create connector enum property (e.g a property which will list > supported output encodings - like yuv420, yuv422 etc) whose list of > supported enum values could be changed dynamically e.g. based on which sink > is connected. > > I think there is existing EDID connector property whose value changes based > on connected sink. EDID is a BLOB property, I am trying to understand if this > is also possible for ENUM type property. There is "drm_property_replace_blob" > to replace blob but I wasn't able to find any API which could replace list of > supported enums. Alternatively, would it be good idea to destroy custom enum > property created by a driver and create new enum property with new list of > supported enums e.g when there is a HOTPLUG event.
Neither works, properties and their value ranges are static. Also generally the idea is that the properties on the drm_connector reflect what the source side can do, irrespective of the sink capabilities. Since a lot of sinks have bad EDID and you might want to overwrite what the sink claims works. Usually how we do this is a second property that the kernel sets, and userspace can only read, which shows what the sink is capable of. Sometimes we also just let userspace re-decode the EDID and figure that out itself, but that's kinda a bad interface. Also for anything new, please keep in mind our rules for new uapi: https://dri.freedesktop.org/docs/drm/gpu/drm-uapi.html#open-source-userspace-requirements https://dri.freedesktop.org/docs/drm/gpu/drm-uapi.html#testing-and-validation Cheers, Daniel -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
