scsi_reset(9F)						   Kernel Functions for Drivers 					    scsi_reset(9F)

NAME

       scsi_reset - reset a SCSI bus or target

SYNOPSIS

       #include <sys/scsi/scsi.h>

       int scsi_reset(struct scsi_address *ap, int level);

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI).

PARAMETERS

       ap	       Pointer to the scsi_address structure.

       level	       The level of reset required.

DESCRIPTION

       scsi_reset() asks the host adapter driver to reset the SCSI bus or a SCSI target as specified by level. If level equals RESET_ALL, the SCSI
       bus is reset. If it equals RESET_TARGET, ap is used to determine the target to be reset.  If it equals RESET_LUN, ap is used  to  determine
       the logical unit to be reset.

       When given the RESET_LUN level, scsi_reset() can return failure if the LOGICAL UNIT RESET message is not supported by the target device, or
       if the underlying HBA driver does not implement the ability to issue a LOGICAL UNIT RESET message.

       Note that, at the point when scsi_reset() resets the logical unit (case RESET_LUN), or the target (case RESET_TARGET),  or  the	bus  (case
       RESET_ALL),  there  might  be one or more command packets outstanding. That is, packets have been passed to scsi_transport(), and queued or
       possibly transported, but the commands have not been completed and the target completion routine has not been called for those packets.

       The successful call to scsi_reset() has the side effect that any such commands currently outstanding are aborted, at which point the  pack-
       ets  are  marked with pkt_reason set to CMD_RESET, and the appropriate bit -- either STAT_BUS_RESET or STAT_DEV_RESET -- is set in pkt_sta-
       tistics. Once thus appropriately marked, the aborted command packets are passed to the target driver command completion routine.

       Also note that, at the moment that a thread executing scsi_reset() actually resets the target or the bus, it  is  possible  that  a  second
       thread  may  have  already  called  scsi_transport(), but not yet queued or transported its command. In this case the HBA will not yet have
       received the second thread's packet and this packet will not be aborted.

RETURN VALUES

       scsi_reset() returns:

       1	Upon success.

       0	Upon failure.

CONTEXT

       scsi_reset() can be called from user or interrupt context.

SEE ALSO

       tran_reset(9E), tran_reset_notify(9E), scsi_abort(9F)

       Writing Device Drivers

SunOS 5.10							    12 Jul 2002 						    scsi_reset(9F)