Vayakhel-Pekudei

The Rashba"m on Pesachim 112a says that we learn one must knock before entering from the fact that the Kohen Gadol wore bells on the Ephod, which made it clear that he was entering the Kodesh. If the reason that he wore them is because it's manners to let it be known that he's entering than the other Kohanim should also have to wear bells when they enter the Kodesh!?