linux-dmabuf: clarify DRM_FORMAT_MOD_INVALID

DRM_FORMAT_MOD_INVALID means to derive the modifier from the dmabuf.
It provides legacy support and makes it easier to replace wl_drm.

v3: DRM_FORMAT_MOD_INVALID must be advertised to be supported (which
    requires a version bump)
v4: no version bump, but a note for now

Signed-off-by: Chia-I Wu <>
Reviewed-by: Pekka Paalanen <>
Reviewed-by: Simon Ser <>
Reviewed-by: Daniel Stone <>
1 file changed