Re: [PATCH 5/6] hisi_sas: add hisi_sas_slave_configure()

From: John Garry
Date: Mon Feb 22 2016 - 05:02:52 EST



I would like to make another point about why I am making this change
in case it is not clear. The queue full events are form
TRANS_TX_CREDIT_TIMEOUT_ERR and TRANS_TX_CLOSE_NORMAL_ERR errors in
the slot: I want the slot retried when this occurs, so I set status
as SAS_QUEUE_FULL just so we will report DID_SOFT_ERR to SCSI
midlayer so we get a retry. I could use SAS_OPEN_REJECT
alternatively as the error which would have the same affect.
The queue full are not from all slots being consumed in the HBA.

Ah, right. So you might be getting those errors even with some free
slots on the HBA. As such they are roughly equivalent to a
QUEUE_FULL SCSI statue, right?
So after reading SPL I guess you are right here; using tags wouldn't
help for this situation.


Yes, I think we have 90% of slots free in the host when this occurs for one particular test - Our v2 hw has 2K slots, which is >> cmd_per_lun. The errors are equivalent to queue full for the device.

Thanks,
John

Cheers,

Hannes