On Fri, Jun 10, 2016 at 2:19 AM, Hannes Reinecke <hare@xxxxxxx> wrote: > 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. That is good to know there are some vendors that are on the ball. > 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. Agreed. Thanks! > 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) -- Shaun Tancheff -- 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
