If you click the Calls-button in the Opportunity-view, a new window opens with the opportunity name as the Call Summary (prefilled); the calls are not linked to the opportunity, so I don't have a complete history of all the calls linked to this opportunity.

Is there a means to link the call automatically to the opportunity if you click Calls ?

(In fact, it should be similar to the Partner view. If you click the Calls-button, a new window opens up with all the calls linked to the Partner (filtered results)