For support of Adaptec's family of Fast and Ultra SCSI products for the PCI bus, please refer to the adsl(7) manual page. This includes host adapters such as the AHA-294x, AHA-294xW, AHA-294xUW, AHA-2940AU, AHA-394x, AHA-394xW, AHA-394xUW, AHA-394xAUWD, and AHA-4944UW, as well as any motherboard using the AIC-7850, AIC-7855, AIC-7860, AIC-7870, AIC-7880, and AIC-7895 SCSI chips.
This driver coplies with the Storage Device Interface (SDI), enabling SDI-compliant target drivers (such as sd01 and st01 )to communicate on the SCSI bus with target controllers and logical units. This allows normal access to mass-storage devices using standard system interfaces and filesystems.
It is also possible for an application to access the SCSI bus subsystem directly by using the pass-through interface. See pt_open(3X). Exercise extreme caution when using the pass-through interface. It is possible to interfere with normal system I/O and cause hangs if pass-through is used to an active device. Pass-through should only be used to a device that is otherwise quiescent.
The Adaptec PCI host adapter driver honors the command timeout values as specified in the scb structure; see the scb(D4sdi) manual page. A software watchdog timer enforces the processing time limit. When the watchdog timer detects a job that has exceeded its processing time limit, it attempts to abort the job with a SCSI Job Abort Message. The driver also enforces a time limit on the abort process, thereby ensuring that jobs that ``time out'' are reported to the sending SDI Target Driver whether or not the abort succeeds.