PCI_IDE_RESERVED_STREAM_ID
val |= FIELD_PREP(PCI_IDE_SEL_CTL_ID, PCI_IDE_RESERVED_STREAM_ID);
val |= FIELD_PREP(PCI_IDE_LINK_CTL_ID, PCI_IDE_RESERVED_STREAM_ID);
stream_id == PCI_IDE_RESERVED_STREAM_ID ? "reserved" :
reserve_stream_id(hb, PCI_IDE_RESERVED_STREAM_ID);