Hi Harlald,
I have checked my lineage to Petronius and he is my 44th great grandfather and find that the son of Pepin II d'Heristal, Mayor of the Palace of Austrasia is Dreux, duc de Champagne et Bourgogne, my 33rd great grandfather, not Charles Martel.
However, when I checked other children of Pepin II, I found the following
"Father of Geringald; Talendus; Berthe; Dreux duc de Champagne et Bourgogne (my 33rd great grandfather); Grimoald II the Younger; Gertrude D'austrasia, "The Holy" Bastard; Childebrand I de Parracy, duke of Burgundy; Charles "Martel", Prince of the Franks and Gerard."
Therefore, there is more that one line to Petronius Maximus.
I have checked the contributors of these two ancestors of mine. Petronius Maximus was added by Sven Terclavers on March 5, 2007. Pepin II was added by Jean Paul Ancey on January 25, 2007. Because they are not the same people, the information provided by two different sources is credible.
I hope this helps.
Best regards,
John Pat