to replace the very poor, original implementation of Scatter/Gather operations.
Use a bit (that was freed up with the rewrite above) in the SCB control byte
to designate commands that should allow disconnection. The kernel driver
makes this decision now instead of the sequencer since the sequencer can't
do the indexing very efficiently.
This commit drops the sequencer from 426 instructions to 390 most likely
freeing enough space to do a target mode implementation.
The first could occur because the original code would continue to reset
the SCSIID register while waiting for a selection. This could potentially
conflict with a reconnect since a successfull reconnect will also set the
SCSIID register. The fix is to use a separate wait loop after starting
a selection (as was done a few revisions ago).
The second probably never happens, but it was possible for a target to
reconnect while there was a pending SCB on the waiting list and not get
noticed. The fix was to remove a supurflous check of the scb waiting
list.
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.
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().
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.
were two races:
- q_to_b() might unexpectedly return 0 (e.g, after a keyboard signal
flushes the output queue and isn't echoed). ansi_put() interprets
0 bytes as 4GB...
- more output (e.g. for echoes) might arrive afer q_to_b() returns 0.
Then scstart() returns presumably and the new output might not be
handled for a long time.
Remove unused function scxint().
Fix prototypes (foo() isn't a prototype).
syscons' output is now only about 4-5 times slower than I want.
It loses a factor of 2 for scrolling output by unnecessarily copying
the screen buffer, a factor of 4/3 for dumb OPOST processing, and
a factor of 3/2 for clist processing.
- use pseudo-dma
- provide the same features and interface as sio
- support multiple boards
- fix bugs.
Some compile-time configuration constants are set to support higher
speeds and Cyclom-16Y's at a 30% relative cost in efficiency.
Cyclom-16Y support is untested.
form to do this than it is relying on individual subroutines (the logic
in epioctl is itself very minimal). Ideally, unnecessary splimp()'s should
now be removed if they exist; I'll leave this for a later date (a complete
code review of the driver needs to be done). Fixes a bug I noticed that
would show up when ifconfig'ing the interface down.
is needed for 3940 support.
Have tagged commands look to see if a target is "busy" with a non tagged
command before executing. This prevents overlapped tagged and non tagged
commands which can happen since request sense commands are not tagged.
people tend to assume their devices won't work if they see this
message, though it may indicate that those devices just don't
need any PCI driver (e.g. devices that emulate an ISA card, or
that have been initialised by the BIOS and need no further care).
no ports are active, provided there are no polled ports and no
`LOSESOUTINTS' ports. Do a little more in the interrupt handler instead.
This is a little less efficient if there are are many active ports but
a little more efficient otherwise. Polled ports are ones with no irq
specified (as before). `LOSESOUTINTS' ports are ones with 0x08 set in
their config flags. Unless this flag is set, it will now take up to one
second to recover from lost output interrupts, if any. Some 8250s and
16450s lose output interrupts.
Improve output buffering: copy the clist buffer to 2 linear buffers if
necessary and possible instead of to 1. Handle an arbitrary queue of
buffers in the interrupt handler. Check for waking up sleepers after
copying characters out of the clist buffer instead of before.
Delay translation of TIOCM_DTR to MCR_DTR etc. so that the top level
routines are more machine independent.
Fix bogus device register in unused code.
etc.). The tulip_start routine was rewritten to use less stack space (I've
been having problems with wcarchive overflowing the stack and this should
help a little). This version also has preliminary NetBSD support.
Rod Grimes helped in testing this version of the driver. Thanks Rod. It's
additionally been extensively tested here and on wcarchive.
Submitted by: Matt Thomas
to most users (the wrong length is passed to ether_input). The
second is more serious. The multicast hash algorithm uses the wrong
(low) bits instead of the right (high) bits. This is only an issue
if you use >12 multicast addresses but if you are using IP multicast
then it might affect you...
Submitted by: Matt Thomas
thrown out if bpfilter support and no BPF listener. (submitted by Bill
Fenner)
Removed unused variable and changed another from a stack variable to a
static - the variable was a rather large array of structs that consumed
a lot of stack space. (me)
1) If a target initiated a sync negotiation with us and happened to chose a
value above 15, the old code inadvertantly truncated it with an "& 0x0f".
If the periferal picked something really bad like 0x32, you'd end up with
an offset of 2 which would hang the drive since it didn't expect to ever
get something so low. We now do a MIN(maxoffset, given_offset).
2) In the case of Wide cards, we were turning on sync transfers after a
sucessfull wide negotiation. Now we leave the offset alone in the per
target scratch space (which implies asyncronous transfers since we initialize
it that way) until a syncronous negotation occurs.
3) We were advertizing a max offset of 15 instead of 8 for wide devices.
4) If the upper level SCSI code sent down a "SCSI_RESET", it would hang the
system because we would end up sending a null command to the sequencer. Now
we handle SCSI_RESET correctly by having the sequencer interrupt us when it
is about to fill the message buffer so that we can fill it in ourselves.
The sequencer will also "simulate" a command complete for these "message only"
SCBs so that the kernel driver can finish up properly. The cdplay utility
will send a "SCSI_REST" to the cdplayer if you use the reset command.
5) The code that handles SCSIINTs was broken in that if more than one type
of error was true at once, we'd do outbs without the card being paused.
The else clause after the busfree case was also an accident waiting to
happen. I've now turned this into an if, else if, else type of thing, since
in most cases when we handle one type of error, it should be okay to ignore
the rest (ie if we have a SELTO, who cares if there was a parity error on
the transaction?), but the section should really be rewritten after 2.0.5.
This fix was the least obtrusive way to patch the problem.
6) Only tag either SDTR or WDTR negotiation on an SCB. The real problem is
that I don't account for the case when an SCB that is tagged to do a particular
type of negotiation completes or SELTOs (selection timeout) without the
negotiation taking place, so the accounting of sdtrpending and wdtrpending
gets screwed up. In the wide case, if we tag it to do both wdtr and sdtr,
it only performs wdtr (since wdtr must occur first and we spread out the
negotiation over two commands) so we always have sdtrpending set for that
target and we never do a real SDTR. I fill properly fix the accounting
after 2.0.5 goes out the door, but this works (as confirmed by Dan) on
wide targets.
Other stuff that is also included:
1) Don't do a bzero when recycling SCBs. The only thing that must explicitly
be set to zero is the scb control byte which is done in ahc_get_scb. We also
need to set the SG_list_pointer and SG_list_count to 0 for commands that do
not transfer data.
2) Mask the interrupt type printout for the aic7870 case. The bit we were
using to determine interrupt type is only valid for the aic7770.
Submitted by: Justin Gibbs
the 802.3 frames generated by the DC21040 (which does automatic padding
of less-than-minimum frames) and the frames generated by the 'ed'
driver, I've found that there is indeed a bug in the size of "ETHER_MIN_LEN"
as reported by several people, John Hay being the most recent. The driver
was actually setting the length to 6+6+2+50 (64 bytes), which when adding
in the CRC (which is automatically appended to the frame and not included
in the length), the minimum frame is 4 bytes larger than it is supposed to
be. All of this is confirmed by tcpdump showing 50 bytes of data for
minimum frames from the 'ed' cards and 46 bytes from 'de' cards. This
analysis has also revealed that there is garbage in the un-filled in
portion at the end of the minimum frames from the 'ed' driver; I don't
plan to fix this.
