From: Nick Cheng on
1. To support instantaneous report for SCSI device existing by periodic
2. In arcmsr_iop_xfer(), inform AP of F/W's deadlock state to prevent
endless waiting
3. To block the coming SCSI command while the driver is handling bus reset
4. To support HW reset in bus reset error handler
Signed-off-by: Nick Cheng< nick.cheng(a) >