One thing I noted from the FOSDEM talk is that even though Qualcomm supports mainlining through Linaro, it's done based on existing code (both NDAed and public)

One thing I noted from the FOSDEM talk is that even though Qualcomm supports mainlining through Linaro, it's done based on existing code (both NDAed and public) and there's close to no documentation provided neither publicly nor privately to the devs. When you'll happen to work on that code in the future in mainline Linux trying to catch some bug, all you'll have to cross-check things with may be the same buggy code you try to fix - so in the end it's just like it would be reverse engineered, but without all the notes that community may have produced while trying to understand the thing.