On Fri, 13 May 2005 15:19:39 +1000, Douglas Gilbert wrote: >Doug Maxey wrote: >> ahem, the neural pathways are not just worn, they have become ruts. =) >> >> s/mode/vpd/. >> >> On Wed, 11 May 2005 13:01:25 CDT, Doug Maxey wrote: >> >>>Howdy, >>> >>>When a ATA/ATAPI device is attached via libata, what should the handling >>>be for mode pages that do not exist in the device? >>> >>>Assuming the page being asked for is 0x83, should libata fake up the >>>page from the IDENTIFY (PACKET) DEVICE data? Or should it just respond >>>there is no page 0x83 as it does now in INQUIRY? Likewise for 0x80? > >Doug, >For ATAPI, the packet interface is almost always >carrying a SCSI command set (exceptions anybody??), call it 95% SCSI, and I will agree. >typically MMC (for CD/DVD drives). Recent SPC-3 drafts >(to which MMC-4,5 should comply) have made the device >identification VPD page (0x83) mandatory. I haven't >seen any compliance yet (or for that matter a drive that >implements feature 0x108: LU serial number). I have recently been looking at the specs for a rebranded Panasonic Slimline DVD/RAM/+R/+RW drive. The EVPD bit on the inquiry page is marked as optional, but returns CHECK CONDITION if set, and you get a 5/24/00 back. :-/ So even if the device had the pages, we can't get to them. Nowhere in the device spec is there an indication they even exist. Of the few ATAPI drive specs I have seen, this seems to be the standard behavior. The data (serial number, anyway), is ostensibly available from the IDENTIFY DEVICE data. However, the bytes available are invariably smashed to a sequence of 0x20. Lastly, looking at a recent version of MtFuji 6.08, support for the EVPD bit is optional. I just suspect it's one of those things that is interpreted as a MUST NOT implement in the cost conscious manufacturing environment. Nor are there any references to VPD data other than the Standard INQUIRY data. > >For ATA, work is being done on a SCSI-ATA Translation >draft standard see: >http://www.t10.org/ftp/t10/drafts/sat/sat-r03.pdf >section 8.1.3.3 . > Ah yes, the other 90% of ATA. But that is just for disks. The optical drive vendors seem to pretty closely follow ftp://ftp.avc-pioneer.com/Mtfuji_6/Spec/Fuji6r08.pdf >Doug Gilbert > ++doug - : 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
