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At 13:54 29-01-2003, Elliott, Robert (Server Storage) wrote:
Actually it's a trivial change for ATAPI. All it requires is that the protocol spec (ATAPI spec) require that the host (SCSI initiator) issue a REQUEST SENSE immediately after receiving a CHECK CONDITION status. This is the way the ATAPI protocol would "implement" autosense. The observable behavior is identical to the present. All we've done is move the CHECK CONDITION -> REQUEST SENSE handshake from SAM-n to ATAPI.Adding autosense to ATAPI would be a significant change in the protocol.
Rob, I recall discussing with Ralph Weber, John Lohmeyer, et.al. several years ago. I guess you weren't there. The discussion was triggered by the recognition that the old CAM spec required that autosense be emulated for parallel SCSI by having the CAM SIM layer automatically issue a REQUEST SENSE. The conclusion was that, while possible, this "spec hack" would cause more confusion than it solved. It's particularly straightforward for an inherently single host / single initiator bus like ATAPI; there are some warts with multi-initiator configurations.
Edward A. Gardner [EMAIL PROTECTED]
Basil Networks 719 593-8866 CO voice
1262 Hofstead Terrace 719 210-7200 cell
Colorado Springs, CO 80907 408 635-8741 CA voice
