>>>>> "James" == James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> writes: James> I'd really rather not put transport specific knowledge back into James> the mid-layer ... the whole idea of the transport classes was to James> take it out as much as possible. I felt that implementing transport classes for everything else was a huge overkill for a simple identifier. James> The other thought is that a lot of devices nowadays are bridged James> (all SCSI DVDs have SPI to ATA bridges; a lot of high end USB James> storage or enclosures has USB to ATA bridges), so a single James> transport identifier doesn't quite cover it. Nope. And it was not means to be concise. It was meant to be a hint as to what kind of technology was at play. To a large extent a dubious_transport bit would suffice. But I also wanted to remedy the lsscsi problem while I was at it. As Doug mentioned the current heuristics are icky. James> The final thought is that a lot of what you're looking for is James> actually in the PROTOCOL field of a VPD inquiry, so it might be James> possible to use that to obviate a lot of this. You mean the protocol mode page? Or the version descriptors in INQUIRY? I don't have a single device that provides the version descriptors. Sadly. I'm fine with the mode page approach, although a quick test shows only very recent drives fill it out. I'll try it on all my spindles in the lab and see what I discover. Maybe we can reverse the logic a bit and key off of whether the protocol mode page is provided. And consider devices dubious if it's not? The thing is we need to start sending RC16 to a lot of drives very soon because of the 4KB thing. And as we've seen RC16 breaks a lot of junk devices. So we need a good indicator other than the SCSI rev. because that unfortunately doesn't cut it. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: 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
