On 10 August 2016 at 15:41, David Milburn <dmilburn@xxxxxxxxxx> wrote: > Hi, > > The 168 makes AHCI_CMD_TBL_SZ equal to 2816 > > AHCI_CMD_TBL_SZ = AHCI_CMD_TBL_HDR_SZ + (AHCI_MAX_SG * 16) > AHCI_CMD_TBL_SZ = 128 + (168 * 16) > > I think if you add in AHCI_CMD_SLOT_SZ (1024) and AHCI_RX_FIS_SZ (256) > the DMA is 4K aligned, I think that is where the 168 came from. Looks like the right guess. Though AHCI_PORT_PRIV_DMA_SZ is not: AHCI_CMD_SLOT_SZ (1024) + AHCI_CMD_TBL_SZ (2816) + AHCI_RX_FIS_SZ (256) = 4096 but: AHCI_CMD_SLOT_SZ (1024) + AHCI_CMD_TBL_AR_SZ (2816 * 32 = 90112) + AHCI_RX_FIS_SZ (256) = 91392 and AHCI_PORT_PRIV_FBS_DMA_SZ is: AHCI_CMD_SLOT_SZ (1024) + AHCI_CMD_TBL_AR_SZ (2816 * 32 = 90112) + AHCI_RX_FIS_SZ * 16 (4096) = 95232 > > Thanks, > David > > -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
