Fix a case in ndling ATA_PASSTHROUGH commands that have an unaligned buffer.
This impacts some home-rolled SMART tools.
In rare cases, a SATA drive can stop responding to commands and trigger a
reset device task request from the driver. If the drive fails to respond
with a signature FIS, the driver would previously get into an endless retry
loop, stalling all I/O to the drive and keeping user processes stranded.
Instead, fail the i/o and invalidate the device if the task management
command times out. This is controllable with the sysctl and tunable
hw.isci.fail_on_task_timeout
dev.isci.0.fail_on_task_timeout
The default for these is 1.
Obtained from: Netflix, Inc.
c80125f577