In my own opinion, knocked and waited are two different verbs. They share the same subject, which makes me confused about why two verbs can be joined by a comma. I think knocking is more appropriate or add "and" where comma has been used.
This is a excerpt from A Rose for Emily by William Faulkner
They called a special meeting of the Board of Aldermen. A deputation waited upon her,knocked at the door through which no visitor had passed since she ceased giving china-painting lessons eight or ten years earlier.