st0 at atapibus0 drive 1: <Seagate STT8000A, , 5.51> type 1 sequential
removable
Major changes may still happen in order to properly support other ATAPI
tape drives.
Add SD_IO_TIMEOUT (an option in opt_scsi.h) also, which defaults to the
normal 60 * 1000 timeout for normal read/write commamds. This allows you
to shorten or lengthen the timeout as needed.
some devices can't handle tag number larger than some values and always
reject commands with QUEUE FULL if the tag number is larger than this.
Under some circonstances the scsipi system may not decrease periph_openings
(as a workaround of other odd behavior) and we may end up requeuing the command
with a hight tag value again, and the driver could loop on this.
Workaround: in case of queue full, decrease periph_openings to
min(periph_active - 1, periph_openings - 1) so that, after some iteration,
periph_openings is less than the max tag value acceptable by the device.
Solves the problem with tagged queuing on ncr53c9x for me.
This is a completely rewritten scsipi_xfer execution engine, and the
associated changes to HBA drivers. Overview of changes & features:
- All xfers are queued in the mid-layer, rather than doing so in an
ad-hoc fashion in individual adapter drivers.
- Adapter/channel resource management in the mid-layer, avoids even trying
to start running an xfer if the adapter/channel doesn't have the resources.
- Better communication between the mid-layer and the adapters.
- Asynchronous event notification mechanism from adapter to mid-layer and
peripherals.
- Better peripheral queue management: freeze/thaw, sorted requeueing during
recovery, etc.
- Clean separation of peripherals, adapters, and adapter channels (no more
scsipi_link).
- Kernel thread for each scsipi_channel makes error recovery much easier
(no more dealing with interrupt context when recovering from an error).
- Mid-layer support for tagged queueing: commands can have the tag type
set explicitly, tag IDs are allocated in the mid-layer (thus eliminating
the need to use buggy tag ID allocation schemes in many adapter drivers).
- support for QUEUE FULL and CHECK CONDITION status in mid-layer; the command
will be requeued, or a REQUEST SENSE will be sent as appropriate.
Just before the merge syssrc has been tagged with thorpej_scsipi_beforemerge
saves about 2.2MB under /usr/include/dev/. Discussed on tech-kern@
recently.
I HOPE to get the list right. The headers I left in are ones
used for MI tools and those whose usage I discovered by grep over tree sources.
Feel free to put needed includes back in if you encounter anything which
should not be removed from lists.
the number of partitions is > OLDMAXPARTITIONS. This is better
than silently truncating the label (don't want to silently throw
away partitions when using an old disklabel binary on a label with
> 8 partitions). From Enami Tsugutomo.
lukem