Messages in this thread | | | Date | Thu, 27 Aug 1998 00:16:40 +0300 (IST) | From | Gadi Oxman <> | Subject | Re: ide-scsi multiplies cd-roms for quite some time... |
| |
On Wed, 26 Aug 1998, Janos Farkas wrote:
> > However, multi-lun ATAPI devices do exist. An ATAPI PD-CD device will > > be detected as a SCSI disk drive on LUN 0 and as an ATAPI cdrom on LUN > > 1. > > Ok, then very few things can be done about it, and probably none of it > is really ide-scsi specific... Unless there is a hint on these devices > that the LUN handling is not complete.
According to the specs, new ATAPI devices should report whether they support multiple luns using a previously reserved field in the ATAPI IDENTIFY DEVICE command (bits 0-2 of word 126 contain the last lun identifier).
I preferred not checking the above bits and allowing the multiple-lun probe in any case, since in the worst case we can just identify a single-lun device several times and we won't be using the extra devices, but in the alternative option we might mis-identify a real multi-lun device as a single-lun device, and not have access to the additional luns.
> With these small sample I can > see (maybe 2-3 hosts) I can't say it's really a common case. > Maybe the SCSI subsystem could be prepared to detect identical devices > by serial numbers? Although that doesn't sound too healthy... I guess > very few people has broken and non-broken devices (LUN-wise) in the same > system. > > -- > Janos - Don't worry, my address is real. I'm just bored of spam.
I see a blacklist in scsi.c with the "BLIST_SINGLELUN" and "BLIST_FORCELUN" options, so it looks like there are also real single-lun SCSI devices which report themself as multi-lun devices, and vice-versa.
Gadi
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html
| |