Comment by david-gpu

Speaking from the perspective of somebody who used to do this for a living.

> But the incentive to making something open source is that someone might improve your work

Device drivers, particularly on mobile, aren't evergreen sorts of software. New hardware is released several times a year, and maintenance after shipping is limited to critical issues. By the time it hits the market, the people who developed that driver have moved on to newer products.

> It is somewhat arrogant to assume that nobody else out there could possibly improve this code or add value

Whatever they did would have completely missed the release schedule. It may provide value to people who want to keep using a 10 year old phone, but how does that benefit a company that only makes income when they sell new models?

> Just like it is arrogant to assume that your competitors don't already know your 'secrets' and haven't reverse engineered anything they found interesting.

This made me laugh. You would be surprised by how minimal reverse engineering goes on in this space. It boils down to the same reason as before: by the time you have made any progress, the product you are reverse engineering is semi obsolete. The vast majority of the time it makes more sense to invest those resources into developing your own stuff.

That's my $.02 from having worked for four major GPU vendors out there. Upper management knows what they are doing, even if outsiders don't get it. The incentives simply aren't there for most GPU vendors most of the time.