The Adaptec PCI host adapter driver enables 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.
You can access the SCSI bus subsystem directly by using the driver's pass-through interface. This allows the user to issue sb control blocks directly to a SCSI target device. To find the appropriate pass-through device to use for a particular target device, the user should open(2) the character special file for the device in question and then issue the B_GETDEV ioctl (see ioctl(2)). The device value returned should then be used to create a character special file which, when opened, can be used for pass-through (SDI_SEND) ioctl.
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.