SAMV7 USBDEVHS: A problem occurred if the USB cable is unplugged while a large...

SAMV7 USBDEVHS: A problem occurred if the USB cable is unplugged while a large amount of data is send over an IN endpoint using DMA. If the USB cable is plugged in again after a few seconds it is not possible to send data over this IN endpoint again, all other endpoints work as expected.

The problem occurs because if the USB cable is unplugged while an DMA transfer is in flight the transfer is canceled but the register SAM_USBHS_DEVDMACTRL is left in an undefined state.  The problem was fixed the problem by resetting the register SAM_USBHS_DEVDMACTRL to a known state. Additionally all pending interrupts are cleared.