RE: end to end error recovery musings

["Martin K. Petersen" <martin.petersen@oracle.com>]

>>>>> "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