Negotiation On Reselection

Ashok Raj ashokr at pyramid.com
Wed Mar 12 09:32:01 PST 1997


* From the SCSI Reflector (scsi at symbios.com), posted by:
* ashokr at pyramid.com (Ashok Raj)
*
[ ASpaldin at corp.adaptec.com wrote...]
> 
> * From the SCSI Reflector (scsi at symbios.com), posted by:
> * ASpaldin at corp.adaptec.com
> *
> Form: Memo
> Text: (17 lines follow)
> Does anyone know if Initiators would have a problem with a target which 
> renegotiated on a reselection. The SCSI spec do not seem to disallow this.
> 
> For example, an Initiator sends the Target a READ command and allows 
> disconnection. The Target disconnects at the end of Command phase. At some 
> time later the Target reconnects and transfers some data and disconnects. 
> The Target then  reconnects (reselection) again to send some more data and 
> decides to renegotate( sends WDTR and or SDTR messages after sending the 
> Identify message). 

I have seen IBM 4gb disks do something like this. But not ina situation 
as described above, except in a case of poweron reset. 

If the initiator does not want to handle wide/sync at this point
we would send a msg reject after setting atn, and that would help
the target understand thats something the initiator is not ready to 
handle, and would just behave in narrow mode. 

if we are ready to regotiate from the initiator, then we set atn and 
send the acceptable parm back to drive, and clear atn. 



> 
> Cheers
> alan         
> 
>  
> 
> alan spalding
> email: alan_spalding at corp.adaptec.com
> Use Proportional Font: true
> *
> * For SCSI Reflector information, send a message with
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> 


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