On Wed, Oct 14, 2015 at 10:20:50AM +0200, Peter Zijlstra wrote: > Uuh, I just looked at next and saw this regulator_lock_supply() > function. How is that limited? subclass must be <8 otherwise bad things > happen.
Can we please get some more discoverable documentation of the arbitrary limits in the lockdep code? I seem to keep seeing code that bumps into surprising limits like this and I'm not sure how I'm supposed to know about them except through finding out after the fact or trawling the code every time someone touches locking. I would be very surprised to see a system that pushes over 8 locks, while there's nothing actually preventing it system design considerations mean that even four cascaded supplies are pretty unlikely so we should be fine. Every time you add a new level of regulation you're both increasing the load on regulators up the chain (which means they need to be bigger and more expensive) and except in the case of a DCDC supplying an LDO (which only works to one level) you're going to be decreasing the efficiency of the system. If we get to that point we can worry about what to do.
signature.asc
Description: PGP signature
