RE: end to end error recovery musings

Martin K. Petersen
2007-02-28T17:28:03Z

>>>>> "Eric" == Moore, Eric <Eric.Moore@lsi.com> writes:

[Trimmed the worldwide broadcast CC: list down to linux-scsi]

Eric> I from the scsi lld perspective, all we need 32 byte cdbs, and a
Eric> mechinism to pass the tags down from above.

Ok, so your board only supports Type 2 protection?

Eric> It appears our driver to firmware insterface is only providing
Eric> the reference and application tags.

My current code allows the submitter to specify which tags are valid
between the OS and the HBA. Your inbound scsi_cmnd will have a
protection_tag_mask which tells you which fields are provided.

Similarly, there's a mask in scsi_host which allows the HBA to
identify which protection types it supports. I hadn't envisioned that
an HBA might only provide a subset. I'll ponder a bit.

Eric> I assume that for transfers greater than a sector, that the
Eric> controller firmware updates the tags for all the other sectors
Eric> within the boundary.

In other words you only support one app tag per request and not per
sector?

--
Martin K. Petersen Oracle Linux Engineering