Solaris DDI specific (Solaris DDI)

The SCSI-2standard defines a status byte that is normally sent by the target to the initiator during the status phase at the completion of each command.

uchar  sts_scsi2    :1;       /* SCSI-2 modifier bit */
uchar  sts_is       :1;       /* intermediate status sent */
uchar  sts_busy     :1;       /* device busy or reserved */
uchar  sts_cm       :1;       /* condition met */
ucha   sts_chk      :1;       /* check condition */

sts_chk indicates that a contingent allegiance condition has occurred.

sts_cm is returned whenever the requested operation is satisfied

sts_busy indicates that the target is busy. This status is returned whenever a target is unable to accept a command from an otherwise acceptable initiator (that is, no reservation conflicts). The recommended initiator recovery action is to issue the command again later.

sts_is is returned for every successfully completed command in a series of linked commands (except the last command), unless the command is terminated with a check condition status, reservation conflict, or command terminated status. Note that host bus adapter drivers may not support linked commands (see scsi_ifsetcap(9F)). If sts_is and sts_busy are both set, then a reservation conflict has occurred.

sts_scsi2 is the SCSI-2 modifier bit. If sts_scsi2 and sts_chk are both set, this indicates a command terminated status. If sts_scsi2 and sts_busy are both set, this indicates that the command queue in the target is full.

For accessing the status as a byte, the following values are appropriate:

STATUS_GOOD

This status indicates that the target has successfully completed the command.

STATUS_CHECK

This status indicates that a contingent allegiance condition has occurred.

STATUS_MET

This status is returned when the requested operations are satisfied.

STATUS_BUSY

This status indicates that the target is busy.

STATUS_INTERMEDIATE

This status is returned for every successfully completed command in a series of linked commands.

STATUS_SCSI2

This is the SCSI-2 modifier bit.

STATUS_INTERMEDIATE_MET

This status is a combination of STATUS_MET and STATUS_INTERMEDIATE.

STATUS_RESERVATION_CONFLICT

This status is a combination of STATUS_INTERMEDIATE and STATUS_BUSY, and it is returned whenever an initiator attempts to access a logical unit or an extent within a logical unit is reserved.

STATUS_TERMINATED

This status is a combination of STATUS_SCSI2 and STATUS_CHECK, and it is returned whenever the target terminates the current I/O process after receiving a terminate I/O process message.

STATUS_QFULL

This status is a combination of STATUS_SCSI2 and STATUS_BUSY, and it is returned when the command queue in the target is full.

scsi_ifgetcap(9F), scsi_init_pkt(9F), scsi_extended_sense(9S), scsi_pkt(9S)

Writing Device Drivers