[vidarh]

Linux very intentionally and explicitly do not guarantee a stable interface for drivers. If you want to maintain your driver out of tree, then that's your right, but you have to be prepared for Linux kernel maintainers to break your driver regularly. The point is they are not interested in sacrificing ability to improve the kernel just in order to make it easier for people to maintain proprietary drivers.

Proprietary drivers are tolerated, not liked, and people aren't interested in making it easier for them.

[dahauns]

Except that this is in no way specific to proprietary drivers. Lack of a stable interface makes maintaining ALL drivers harder.

[wtallis]

These interfaces aren't broken gratuitously. They change to accommodate new features or to allow for better code reuse within the kernel. In the long term it's only a significant maintenance burden compared to letting the driver stagnate and never gain new functionality or optimization after initial release. Manufacturers might prefer that development model since it helps sell more chips of the next generation, but it's really not what should be used as the baseline.

[prodigal_erik]

You only have to fix your driver if it's outside the kernel tree. Drivers in the tree get fixed by whoever's making the breaking change (which is why it's important that certain hackers be able to read and understand all related drivers).