> Android devices have been plagued with vendors having out-of-tree device drivers that compile for linux 3.x, but not 4.x or 5.x What's preventing adding a dr

> Android devices have been plagued with vendors having out-of-tree device drivers that compile for linux 3.x, but not 4.x or 5.x What's preventing adding a driver compatibility layer over the unstable API? I would accept a some performance cost and NOPs for new features using a shim for existing legacy binary drivers compared to being forced to junk functioning hardware.