Well, that took a while; to be approximate, more than two weeks.
See, the Orioles wanted Willis to pitch as a reliever in the minors, and Willis wanted to start. Willis eventually left his minor-league team; whether with permission or not, which depends on who you asked.
Here's Jerry Crasnick (via ESPN.com):
Pitcher Dontrelle Willis has agreed to drop his grievance against the Baltimore Orioles after the team granted his request to pitch as a starter in the minor leagues, his agent told ESPN.com.
Willis, 30, will report to extended spring training in Florida this week and try to build up his innings and work his way to Baltimore, agent Matt Sosnick said. The Orioles signed Willis in late March after he was released by the Philadelphia Phillies late in spring training.
What's a little odd about all this is that Willis probably has a better shot at returning to the majors as a relief pitcher. I'll bet a dollar he figures that out, eventually.