This was originally ported to BSDI by Andy Rutter <andy@acronym.co.uk>.
At the end of the day, this code has very little in common with Andy's
version, or the Specialix SYSV version. Essentially it has been gradually
and almost completely rewritten, with LOTS of advice and inspiration from
Bruce Evans. There are a couple of missing bits still, but they are minor.
The user-mode "sicontrol" program is in sad shape and will come in soon.
Transparent printing died a timely death.. Maybe later..
Jeremy Rolls @ Specialix (Development directory) has confirmed this is OK
to distribute, and Andy personally sent me his version that I started from.
Although this driver stood up to a nasty stress-test in this form, I am not
confident that there are no nasty bugs lurking.
People are welcome to try it, but dont go out and buy one just yet.. :-)
And *DONT* use it on a mission-critical machine... This is ALPHA QUALITY!
of "__volatile". Note also that the original mods that were submitted
by me were as a result of a discussion between various FreeBSD contributors.
Submitted by: peter@haywire.dialix.com (Peter Wemm)
for return values. It just so happens that in the cases where it is likely
to fail, it is okay to change the M_NOWAIT to M_WAITOK -- and all will
be well. This problem was manfest as a panic very regularly on a 4MB
system right after bootup.
hardware. Set the sleep-on flag for the address so there is more
than a small chance that the sleep address is actually used (this
used to work by timing out). Don't bother clearing the sleep-on
flag after a timeout here or elsewhere since leaving it set just
generates a few null calls to wakeup().
Introduce TS_CONNECTED and TS_ZOMBIE states. TS_CONNECTED is set
while a connection is established. It is set while (TS_CARR_ON or
CLOCAL is set) and TS_ZOMBIE is clear. TS_ZOMBIE is set for on to
off transitions of TS_CARR_ON that occur when CLOCAL is clear and
is cleared for off to on transitions of CLOCAL. I/o can only occur
while TS_CONNECTED is set. TS_ZOMBIE prevents further i/o.
Split the input-event sleep address TSA_CARR_ON(tp) into TSA_CARR_ON(tp)
and TSA_HUP_OR_INPUT(tp). The former address is now used only for
off to on carrier transitions and equivalent CLOCAL transitions.
The latter is used for all input events, all carrier transitions
and certain CLOCAL transitions. There are some harmless extra
wakeups for rare connection- related events. Previously there were
too many extra wakeups for non-rare input events.
Drivers now call l_modem() instead of setting TS_CARR_ON directly
to handle even the initial off to on transition of carrier. They
should always have done this. l_modem() now handles TS_CONNECTED
and TS_ZOMBIE as well as TS_CARR_ON.
gnu/isdn/iitty.c:
Set TS_CONNECTED for first open ourself to go with bogusly setting
CLOCAL.
i386/isa/syscons.c, i386/isa/pcvt/pcvt_drv.c:
We fake carrier, so don't also fake CLOCAL.
kern/tty.c:
Testing TS_CONNECTED instead of TS_CARR_ON fixes TIOCCONS forgetting to
test CLOCAL. TS_ISOPEN was tested instead, but that broke when we disabled
the clearing of TS_ISOPEN for certain transitions of CLOCAL.
Testing TS_CONNECTED fixes ttyselect() returning false success for output
to devices in state !TS_CARR_ON && !CLOCAL.
Optimize the other selwakeup() call (this is not related to the other
changes).
kern/tty_pty.c:
ptcopen() can be declared in traditional C now that dev_t isn't short.
Use input buffer watermarks of TTYHOG-512 (high) and (high)*7/8
(low) instead of TTYHOG/2 (high) and TTYHOG/5 (low) to agree with
some drivers. 512 is magic and some things depended on TTYHOG/2
>= TTYHOG-512 to work; now they depend on the 512 magic not changing
and TTYHOG-512 being significantly larger than 0. This should be
handled in ttsetwater().
Separate the decision about whether to do input flow control from
doing it. ttyblock() now just starts input flow control (hardware
and/or software) and there is a new function ttyunblock() to stop
it. The decisions are the same except for the watermark changes
and allowing for input expansion for PARMRK.
When flushing input, try harder at first to send a start character
if required, but give up if the first attempt fails.
cy.c, rc.c, sio.c:
Simplify: let ttyinput() handle input flow control if it is not
being bypassed. Use ttyblock() to start flow control otherwise.
rc.c:
Use same input flow control test as elsewhere: test in a more
efficient order and start flow control at >= highwater instead of
at > highwater.
BUS DEVICE RESET followed by BUS RESET failure recovery strategy including
the necesary renegotiation of sync/wide transfers after recovery completes.
Clean up debugging code to make it more finely selectable. Reset code
debugging is enabled for now so I can get more feedback on how this
code behaves in real life.
essential when I fix excessive wakeups for output-below-low-water.
In cy.c and sio.c, wake up via the driver start routine to also
eliminate duplicated code involving the clearing of TS_TTSTOP.
Always (except in code to be replaced soon) call driver start
routine directly instead of going through ttstart().
Amancio. There is some SoundSource support here that is primitive and
probably doesn't work, but I'll let the two submitters let me know
how my integration of that was since I don't have this card to test.
I've only tested this on my GUS MAX since it's all I have.
This all probably needs to be re-done anyway since we're widely variant
from the original VOXWARE source in the current layout.
Submitted by: Amancio Hasty and Jim Lowe
Obtained from: Hannu Savolainen
floppy DMA buffers...use avail_start not "first". Removed duplicate
(and wrong) declaration of phys_avail[].
Submitted by: Bruce Evans, but fixed differently by me.
This finishes making the kernel compile without -O.
The "optimized" asm version of the function being inlined
(translate_bytes()) uses slow instructions. On a 486, assuming
everything is in the cache (unlikely), it is 21/15 times slower
than the dumb C version and 21/3 times slower than the best
possible bytewise method.
didn't work are somewhat bogusly optimized away before the constraint
is checked. We still expect constants passed to inline functions to
remain constant, but if the compiler ever decides that they aren't
constant then it will just generate slightly slower code instead of
an error.
Declare `cheat' as static. It was bogusly shared between the aha1742 and
ultrastor drivers.
Even static variables should have unique names so that they can be
debugged, but fixing them can wait.
ttwwakeup(). The conditions for doing the wakeup will soon become
more complicated and I don't want them duplicated in all drivers.
It's probably not worth making ttwwakeup() a macro or an inline
function. The cost of the function call is relatively small when
there is a process to wake up. There is usually a process to wake
up for large writes and the system call overhead dwarfs the function
call overhead for small writes.
Temporarily nuke TS_WOPEN. It was only used for the obscure MDMBUF
flow control option in the kernel and for informational purposes
in `pstat -t'. The latter worked properly only for ptys. In
general there may be multiple processes sleeping in open() and
multiple processes that successfully opened the tty by opening it
in O_NONBLOCK mode or during a window when CLOCAL was set. tty.c
doesn't have enough information to maintain the flag but always
cleared it in ttyopen().
TS_WOPEN should be restored someday just so that `pstat -t' can
display it (MDMBUF is already fixed). Fixing it requires counting
of processes sleeping in open() in too many serial drivers.
buses on multi-bus controllers. Currently only affects the 274xT controllers.
Reviewed by: Peter Dufault(dufault@hda.com), Rod Grimes(rgrimes@FreeBSD.org)
