On 12/2/05, Jeff Garzik <jgarzik@xxxxxxxxx> wrote: > Bartlomiej Zolnierkiewicz wrote: > > On 11/24/05, Jeff Garzik <jgarzik@xxxxxxxxx> wrote: > > > >>Douglas Gilbert wrote: > >> > >>>I don't think a SATL is that easy. One SCSI command can > >>>translate into zero or more ATA commands. If it translates > >>>to multiple commands, then there is the possibility of an > >>>error prior to the last in the sequence of ATA commands > >>>(how to report; rollback needed ?). The SATL needs to hold > >>>state and needs a service thread if it is to support the > >>>IMMED bit on some commands (e.g. START STOP UNIT). > >> > >>It needs a conceptual service thread, not necessarily an explicit one. > >> > >>With REQUEST SENSE, I've demonstrated how to report errors with each > >>step in the sequence. With demo patches I've posted, I've demonstrated > >>(using qc->private_data) how to hold state. > >> > >> > >> > >>>libata still has a ways to go to catch up to SAT rev 7 > >>>but has made some good progress lately with the addition > >>>of the ATA pass through commands (lk 2.6.15-rc1 and onward). > >>>smartmontools (just prior to 5.34) now works with '-d ata' > >>>on libata-connected SATA disks. The '-d ata' ** overrides > >>>the guess of a SCSI disk based on the device node (e.g. > >>>/dev/sda) and uses the HDIO_DRIVE_CMD and HDIO_DRIVE_TASK > >>>ioctls. The absence of support for the HDIO_DRIVE_TASKFILE > >>>ioctl means that "selective" self-test can't be done. > >>>I'm not sure if moving smartmontools to the ATA PASS THROUGH > >>>SCSI commands will win back the "selective" self-test > >>>capability. Anyway, going to those ATA PASS THROUGH SCSI > >> > >>ATA passthru can do anything the legacy IDE ioctls can do (and more). > > > > > > [ definitely ATA passthru is the way to go but... ] > > > > discrete taskfiles? > > what is this? flagged taskfiles yes, this is a low priority but your statement is oversimplification and I don't even mentioned other "IDE ioctl", so: ATA passthru can do anything _important_ that legacy IDE ioctls can do (write cache [dis,en]abling?) > > multi-PIO? > > what is this? multi-sector PIO, such as READ MULTIPLE SECTORS? ATA short for multi sector-sector PIO > passthru can do that. not in the mainline, I've just checked libata-dev and it is OK > > setting transfer speed? > > That's not a limitation of passthru, but a limitation of the driver. I > don't yet see the value... Same for me... Bartlomiej - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
