On 06/10/2016 09:10 AM, Shaun Tancheff wrote: > The current generation of HBA SAS adapters support connecting SATA > drives and perform SCSI<->ATA translations in hardware. > Unfortunately the ZBC commands are not being translate (yet). > > Currently users of SAS controllers can only send ZAC commands via > ata pass-through. > > This method overloads the meaning of REQ_META to direct ZBC commands > to construct ZAC equivalent ATA pass through commands. > Note also that this approach expects the initiator to deal with the > little endian result due to bypassing the normal translation layers. > > Signed-off-by: Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx> > --- > So this patch isn't the right way to work around hardware that is > missing features (mixing ATA commands in SCSI interface code) it > maybe useful for end users in the near term who have HBA SAS > controllers that don't support ZBC <-> ZAC translations. > And indeed, this patch isn't right. It is just for a very specific SAS HBA (mpt2sas/mpt3sas). Other SAS HBAs like isci and hisi_sas work just nicely here. So a translation into a ATA_16 command is _wrong_. If you need to do this you'll have to move it into the LLDD itself. Or use blacklisting to invoke this behaviour. But _not_ in the general code path. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- 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
