Disable DCAN automatic retransmission?

I’m trying to disable automatic retransmission on DCAN0 without much luck. I’ve tried flipping the bit in the control register manually using devmem2, and I’ve modified the driver so that it sets CONTROL_DISABLE_AR upon device initialization. So far I haven’t had any luck. Does anyone have any ideas to share?

PS I know that automatic retransmission is part of the standard and is generally considered a Good Thing.