RBCTL
rtsx_pci_write_register(pcr, RBCTL, RB_FLUSH, RB_FLUSH);
rtsx_pci_write_register(pcr, RBCTL, RB_FLUSH, RB_FLUSH);
rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, RBCTL,
rtsx_pci_write_register(pcr, RBCTL, RB_FLUSH, RB_FLUSH);
rtsx_pci_write_register(pcr, RBCTL, RB_FLUSH, RB_FLUSH);
rtsx_pci_write_register(pcr, RBCTL, U_AUTO_DMA_EN_MASK, 0);
rtsx_pci_write_register(pcr, RBCTL, 0x80, 0x80);