Hi I understand from the SATA II NCQ specs that for NCQ commands(FPDMA) we need not have to setup the DMA (PRD) for the commands issued but has to do so only on reception of DMA setup FIS from the drive(throught ISR). But in libata/ ata_qc_issue does qc prep and issue irrespective of the protocol. Even i glanced thro' the sil24 driver and seems to be the same. Can someone please guide/ resolve this doubt. Regards Jaychander - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html