MUSB_RXINTERVAL
musb_readb(epio, MUSB_RXINTERVAL);
musb_writeb(epio, MUSB_RXINTERVAL,
musb_writeb(epio, MUSB_RXINTERVAL, 0);
musb_writeb(epio, MUSB_RXINTERVAL, 0);
musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);