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

illumos DDI specific (illumos DDI).

PARAMETERS

ap
Pointer to the scsi_address structure.


level
The level of reset required.

DESCRIPTION

The scsi_reset() function 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 packets
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_statistics. 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

The scsi_reset() function returns:

1
Upon success.


0
Upon failure.

CONTEXT

The scsi_reset() function can be called from user, interrupt, or kernel
context.

SEE ALSO

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


Writing Device Drivers

January 16, 2006 SCSI_RESET(9F)