Thanks for working on this! I've pushed a patch [1] to drm-misc-next which touches the same function, can you rebase your patches on top of it?
[1]: https://patchwork.freedesktop.org/patch/467940/?series=98255&rev=3
- [RFC PATCH 0/3] Add support modifiers for drivers whose pla... Tomohito Esaki
- [RFC PATH 1/3] drm: add support modifiers for drivers ... Tomohito Esaki
- [RFC PATH 2/3] drm: set fb_modifiers_not_supported fla... Tomohito Esaki
- [RFC PATH 3/3] drm: replace allow_fb_modifiers with fb... Tomohito Esaki
- Re: [RFC PATCH 0/3] Add support modifiers for drivers ... Simon Ser
- Re: [RFC PATCH 0/3] Add support modifiers for driv... Esaki Tomohito
