I am primarily making this change in order that the oct612x API can use a mutex as a synchronization primitive. Mutexes can only be aquired in process context and the wct4xxp driver calls the Oct61000InterruptServiceRoutine (which grabs a serialization object) when tone detection is enabled. Signed-off-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>