Before "drm/drm_blend: allow blend mode property without PREMULTI",
userspace would have to assume that only PREMULTI was supported by
drivers that didn't expose the blend mode property. But now userspace
shouldn't rely on that, as they can't count with drivers always
supporting PREMULTI.
Warn if a driver exposes pixel formats with alpha but doesn't expose the
blend mode property. This way userspace doesn't have to guess. Drivers
triggering this warning must be fixed.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Link: https://patch.msgid.link/20260526181700.25310-3-leandro.ribeiro@collabora.com
Signed-off-by: Daniel Stone <daniels@collabora.com>
860e748bdd