Also, adjust message/command construction in ncr53c9x_select() to work no
matter how the structure alignment works out (needed at least for m68k).
Tested by me on mac68k & alpha, and sanity-checked by eeh.
which is revealed with larger HZ systems like NetBSD/pmax (256Hz)
and NetBSD/alpha (1024Hz) as reported by PR#8645. Polled tape
drive access is done with maximum 6 hour timeout which ended up
with negative time and then confused SCSI bus severely.
and scsipi_device respectively, with size reduction of ncr53c9x_softc.
Specifying NULL instructs the driver to use default adapter and default
device codes. Every target port has ncr53c9x_attach(sc, NULL, NULL) anyway.
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
it implemented under the label `shortcut:' and only use it in these
cases: (1) after successful re-relection, (2) after receiving command-complete
status, and (3) during message-in handshake.
for front-ends to override the allocation to avoid alignment
handling in their DMA engines. Note that that ncr53c9x_msgout()
can request a 1 byte DMA transfer that would be difficult to break up.
an initiator/target nexus and thus mark the correct queue (if any) a
command is on.
* If a disconnected command times out, just leave it on the nexus queue
and do nothing (for now). I need yet to decide on the strategy to
follow in this case. Note: we used to move the command to the `ready'
queue and then do nothing, which is worse.
the target still is in MSG OUT phase. We still send a message (a NO_OP)
in this case and the chip will remove ATN at the appropriate time.
Using the RSTATN command here induces a "illegal command" in some
chip revisions.
This situation only occurs if the target rejects a previous (multi-byte)
message early (by switching to MESSAGE IN and sending a MESSAGE REJECT)
before the chip has completed the entire MSG OUT transfer. ATN will
remain asserted, and the target returns to MESSAGE OUT phase.
* Account for the events above when reporting "DMA not completed"
diagnostic messages.
* Stream-line the selection code a bit, and make the DMA setup code
more like the MSG OUT & DATA XFER setup.
petrov