Alan, >>> Only relevant for DMA really >> So rqsize is only needed for DMA accesses? > > PIO transfers are sector at a time, or multi-sector up to a usual limit > of about 16 sectors. So again: rqsize does not matter for PIO transfer? Looking at the lines if (hwif->no_lba48_dma && lba48 && dma) { if (block + rq->nr_sectors > 1ULL << 28) dma = 0; else lba48 = 0; } in drivers/ide/ide-disk.c. Does that mean that 48bit LBA adressing using the task_ioreg_t stuff is only used for sector numbers larger 1 << 28? Thus for small HDDs only LBA28 ist used by hwif->OUTB(block, IDE_SECTOR_REG); hwif->OUTB(block>>=8, IDE_LCYL_REG); hwif->OUTB(block>>=8, IDE_HCYL_REG); ??? Thanks a million!!!! Steven - 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