69599f22f0
- Avoid an additional lock acquire/release when leaving xl_intr(), by changing xl_start*() to xl_start*_locked(), and calling the appropriate routine by chip revision (as the DMA descriptors are different). - Simplify the appropriate routines now that they are called with the lock held. This should save a significant amount of CPU cycles spent on servicing each interrupt for both UP and SMP whilst remaining MPSAFE. Tested by: rwatson