You are right. In this usage case, the counting semaphore is not being used for locking; it is being used for signalling an event per https://cwiki.apache.org/confluence/display/NUTTX/Signaling+Semaphores+and+Priority+InheritanceEven more. In my previous example if semaphore is posted from the interrupt we do not know which of TaskA or TaskB is no longer a "holder l" of a semaphore.
In that case, priority inheritance must be turned off.
