TRAN_RESET(9E) Driver Entry Points TRAN_RESET(9E)

NAME

tran_reset - reset a SCSI bus or target

SYNOPSIS

#include <sys/scsi/scsi.h>


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

INTERFACE LEVEL

illumos architecture specific (illumos DDI).

PARAMETERS

ap
Pointer to the scsi_address(9S) structure.


level
The level of reset required.

DESCRIPTION

The tran_reset() vector in the scsi_hba_tran(9S) structure must be
initialized during the HBA driver's attach(9E) to point to an HBA entry
point to be called when a target driver calls scsi_reset(9F).


tran_reset() must reset either the SCSI bus, a SCSI target device, or a
SCSI logical unit as specified by level.


level must be one of the following:

RESET_ALL
Reset the SCSI bus.


RESET_TARGET
Reset the target specified by ap.


RESET_LUN
Reset the logical unit specified by ap.


tran_reset should set the pkt_reason field of all outstanding packets in
the transport layer associated with each target or logical unit that was
successfully reset to CMD_RESET and the pkt_statistics field must be
OR'ed with either STAT_BUS_RESET (if the SCSI bus was reset) or
STAT_DEV_RESET (if the target or logical unit was reset).


The HBA driver should use a SCSI Bus Device Reset Message to reset a
target device. The HBA driver should use a SCSI Logical Unit Reset
Message to reset a logical unit.


Packets that are in the transport layer but not yet active on the bus
should be returned with pkt_reason set to CMD_RESET and pkt_statistics
OR'ed with STAT_ABORTED.


Support for RESET_LUN is optional but strongly encouraged for new and
updated HBA drivers. If an HBA driver provides RESET_LUN support, it must
also create the lun-reset capability with a value of zero for each target
device instance represented by a valid ap. The HBA is also required to
provide the means to return the current value of the lun-reset capability
in its tran_getcap(9E) routine, as well as the means to change the value
of the lun_reset capability in its tran_getcap(9E) routine.

RETURN VALUES

tran_reset() should return:

1
on success.


0
on failure.

CONTEXT

The tran_reset() function can be called from user or interrupt context.
This requirement comes from scsi_reset().

SEE ALSO

attach(9E), ddi_dma_buf_setup(9F), scsi_hba_attach(9F), scsi_reset(9F),
scsi_address(9S), scsi_hba_tran(9S)


Writing Device Drivers

NOTES

If pkt_reason already indicates that an earlier error had occurred for a
particular pkt, tran_reset() should not overwrite pkt_reason with
CMD_RESET.


August 17, 2005 TRAN_RESET(9E)