PDC_RX_CTL
iowrite32((PDC_RX_CTL + (pdcs->rx_status_len << 1)),
iowrite32((PDC_RX_CTL | PDC_RX_ENABLE | (pdcs->rx_status_len << 1)),
iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),
iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),