Re: PATCH [3/5] qla2xxx: TCQ fixes

Brian King
2004-07-13T02:28:48Z

Mike Christie wrote:
> James Bottomley wrote:
>
>> On Mon, 2004-07-12 at 09:05, Andrew Vasquez wrote:
>>
>>> ChangeSet
>>> 1.1867 04/07/12 09:38:28 andrew.vasquez@apc.qlogic.com +2 -0
>>> Correct usage of tag-command-queueing methods:
>>
>>
>>
>> I really don't think it is.
>>
>> For the way the qla2xxx works, the correct tag usage would be to use per
>> HBA tags (which were introduced for aic7xxx but never used by them, so I
>> haven't actually created the mid-layer API), to populate your queue
>> handle field with the tag and to dispense with your outstanding_cmnds[]
>> array and use scsi_find_tag() to get back the command from the handle.
>>
>> Since you'd be the first user of this API, I'd be happy to come up with
>> it for a willing victim^Wvolunteer.
>
>
> Depending on the API, we might be able to use it for the linux-iscsi
> driver. Today the driver uses scsi_activate_tcq(), but does not uses the
> tag numbers. Instead it uses its own initiator task tags values for
> session wide identifiers, becuase we need tag values for iscsi ops. For
> example if we need to send a ping how should we get a tag from the mid
> layer? Or maybe becuase there are some transport specific tag values
> should we use someting else or keep it in the driver?

ipr is not interested in the tag numbers either, as the adapter
microcode generates them.

--
Brian King
eServer Storage I/O
IBM Linux Technology Center