On 9/21/22 17:24, John Garry wrote:
On 21/09/2022 05:04, Damien Le Moal wrote:
On 9/20/22 19:27, John Garry wrote:
Currently for libata the SCSI device (sdev) associated with an
ata_device
is allocated when the port probe has completed.
It's useful to have the SCSI device and its associated request queue
available earlier for the port probe. Specifically if we have the
request queue available, then we can:
- Easily put ATA qc in SCSI cmnd priv data
- Send ATA internal commands on SCSI device request queue for [0]. The
current solution there is to use the shost sdev request queue, which
isn't great.
This series changes the ata port probe to alloc the sdev in the
ata_device revalidation, and then just do a SCSI starget scan
afterwards.
Why an RFC?
1. IPR driver needs to be fixed up - it does not use ATA EH port probe
Mail [1] needs following up
Yes. If IPR could be converted to ata error_handler, a lot of code can
be simplified in libata too.
Hmmm... yeah, it would be good to see progress there.
2. SATA PMP support needs verification, but I don't have a setup
Port multiplier behind a sas HBA will be challenging to setup :)
I can try, but I will need to open up one of my servers and hook a
small PMP box to one of the pm8001 plugs. I may have the cables for
that... Let me check.
I was more thinking of just AHCI with a port multiplier.
OK. I got confused :)
Easy then, my test box is all hooked up already.
Will give this a spin.
As for SAS controllers, I don't think it's something to be concerned
about. For a start, I know for sure that hisi_sas HW does not support
port multipliers, and I don't think that pm8001 does either. In
addition, libsas does not even support it - I did see a series in the
scsi list from years ago (to support it), but it did not progress.
Thanks,
John
--
Damien Le Moal
Western Digital Research
