fixes the following problems:
- Timeout on START/STOP unit command (ie. when spinning up the drive)
Side effect of this fix is to reduce the busy-wait time in CMD phase.
- Occasionally, the driver would lose an SBIC interrupt, especially when
a tape drive was re-selecting on a busy SCSI bus.
contributed by: Steve Woodford <steve@mctavish.demon.co.uk>
this driver is based on the amiga sbic/33C93 driver. Steve has
cleaned it up and fixed lots of bugs. Note that the original driver
used features which require at least a WD33C93A (the vme147 has the
original WD33C93 chip <no 'A' suffix>). Steve has also written
the DMA routines for the 147 to get things really going. Hardware
scatter-gather DMA and sync. SCSI are not supported (yet). tested
on several disk drives and a tape drive. CD-ROM untested, but
should work.
