STM32 OTG HS DEV (in FS mode): Disable ULPI clock enable in RCC AHB1 Register....

STM32 OTG HS DEV (in FS mode): Disable ULPI clock enable in RCC AHB1 Register.  If Both ULPI and the FS clock enable bits are set in FS mode, then the ARM never awakens froom WFI due to a chip issue.  From Ken Pettit