On 02/06/2018 03:22, John Snow wrote: > - Status: Should be the status register after receiving the H2D Register > update FIS, but prior to the data transfer, I think. "New value of the > Status register of the Command Block for initiation of host data > transfer." > I think this is being set correctly after this patch. > > - Error: "Contains the new value of the Error register of the Command > Block at the conclusion of all subsequent Data to Device frames." > > This is why we were sending out post-hoc PIO Setup FIS frames before, > how would I know what the error register *will* be...? What?
You don't, I guess. Zero? > - LBA: Presumably unimportant for the purposes of receiving a command > PACKET, as we won't be writing it to disk, but a buffer. The values > can be reported dutifully. > > - Device: Just report the register value dutifully. > > - Count: Likely just relays 0, as the H2D REG FIS should have updated > that to zero as part of the PACKET command, as per ATA8 ACS3 7.21.3. > In any case, just report the register value dutifully. > > - E_Status: "Contains the new value of the Status register of the > Command Block at the conclusion of the subsequent Data FIS." > > Again, how would I know...? > > - Transfer Count: Should be 12, as per what we specified in 0xA1 > IDENTIFY PACKET DEVICE, see core.c line 234. Your patch gets this > correct, as we'll actually report the PIO FIS for the packet itself. > > > What this patch does do, though, is change the context of the Status, > Error and E_Status registers to something different. Everything else > should be the same, but I'd feel better about taking this patch if I > understood what exactly this FIS packet was supposed to convey, but I don't. At least Status and Transfer Count are correct after this patch. :/ Paolo
