Tue May 2 00:53:25 1995 <tytso@rsx-11.mit.edu>
* tty_io.c (tty_set_ldisc): Wait until the output buffer is
drained before closing the old line discipline --- needed
in only one case: XON/XOFF processing.
* n_tty.c (n_tty_close): Don't bother waiting until the output
driver is closed; in general, the line discipline
shouldn't care if the hardware is finished
transmitting before the line discipline terminates.
* tty_io.c (release_dev): Shutdown the line discipline after
decrementing the tty count variable; but set the
TTY_CLOSING flag so that we know that this tty structure
isn't long for this world.
* tty_io.c (init_dev): Add sanity code to check to see if
TTY_CLOSING is set on a tty structure; if so, something
bad has happened (probably a line discipline close blocked
when it shouldn't have; so do a kernel printk and then
return an error).
Wed Apr 26 10:23:44 1995 Theodore Y. Ts'o <tytso@localhost>
* tty_io.c (release_dev): Try to shutdown the line discipline
*before* decrementing the tty count variable; this removes
a potential race condition which occurs when the line
discipline close blocks, and another process then tries
open the same serial port.
* serial.c (rs_hangup): When hanging up, flush the output buffer
before shutting down the UART. Otherwise the line
discipline close blocks waiting for the characters to get
flushed, which never happens until the serial port gets reused.
Wed Apr 12 08:06:16 1995 Theodore Y. Ts'o <tytso@localhost>
* serial.c (do_serial_hangup, do_softint, check_modem_status,
rs_init): Hangups are now scheduled via a separate tqueue
structure in the async_struct structure, tqueue_hangup.
This task is pushed on to the tq_schedule queue, so that
it is processed synchronously by the scheduler.
Sat Feb 18 12:13:51 1995 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (disassociate_ctty, tty_open, tty_ioctl): Clear
current->tty_old_pgrp field when a session leader
acquires a controlling tty, and after a session leader
has disassociated from a controlling tty.
Fri Feb 17 09:34:09 1995 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_interrupt_single, rs_interrupt, rs_interrupt_multi):
Change the the number of passes made from 64 to be 256,
configurable with the #define RS_ISR_PASS_LIMIT.
* serial.c (rs_init, set_serial_info, get_serial_info, rs_close):
Remove support for closing_wait2. Instead, set
tty->closing and rely on the line discipline to prevent
echo wars.
* n_tty.c (n_tty_receive_char): IEXTEN does not need to be
enabled in order for IXANY to be active.
If tty->closing is set, then only process XON and XOFF
characters.
Sun Feb 12 23:57:48 1995 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_timer): Change the interrupt poll time from 60
seconds to 10 seconds, configurable with the #define
RS_STROBE_TIME.
* serial.c (rs_interrupt_multi, startup, shutdown, rs_ioctl,
set_multiport_struct, get_multiport_struct): Add
provisions for a new type of interrupt service routine,
which better supports multiple serial ports on a single
IRQ.
Sun Feb 5 19:35:11 1995 Theodore Y. Ts'o (tytso@rt-11)
* tty_ioctl.c (n_tty_ioctl, set_termios, tty_wait_until_sent):
* serial.c (rs_ioctl, rs_close):
* cyclades.c (cy_ioctl, cy_close):
* n_tty.c (n_tty_close): Rename wait_until_sent to
tty_wait_until_sent, so that it's a better name to export
in ksyms.c.
Sat Feb 4 23:36:20 1995 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_close): Added missing check for closing_wait2 being
ASYNC_CLOSING_WAIT_NONE.
Thu Jan 26 09:02:49 1995 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_init, set_serial_info, get_serial_info,
rs_close): Support close_wait in the serial driver.
This is helpful for slow devices (like serial
plotters) so that their outputs don't get flushed upon
device close. This has to be configurable because
normally we don't want ports to be hung up for long
periods of time during a close when they are not
connected to a device, or the device is powered off.
The default is to wait 30 seconds; in the case of a
very slow device, the close_wait timeout should be
lengthened. If it is set to 0, the kernel will wait
forever for all of the data to be transmitted.
Thu Jan 17 01:17:20 1995 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (startup, change_speed, rs_init): Add support to detect
the StarTech 16650 chip. Treat it as a 16450 for now,
because of its FIFO bugs.
Thu Jan 5 21:21:57 1995 <dhinds@allegro.stanford.edu>
* serial.c: (receive_char): Added counter to prevent infinite loop
when a PCMCIA serial device is ejected.
Thu Dec 29 17:53:48 1994 <tytso@rsx-11.mit.edu>
* tty_io.c (check_tty_count): New procedure which checks
tty->count to make sure that it matches with the number of
open file descriptors which point at the structure. If
the number doesn't match, it prints a warning message.
Wed Dec 28 15:41:51 1994 <tytso@rsx-11.mit.edu>
* tty_io.c (do_tty_hangup, disassociate_ctty): At hangup time,
save the tty's current foreground process group in the
session leader's task structure. When the session leader
terminates, send a SIGHUP, SIGCONT to that process group.
This is not required by POSIX, but it's not prohibited
either, and it appears to be the least intrusive way
to fix a problem that dialup servers have with
orphaned process groups caused by modem hangups.
Thu Dec 8 14:52:11 1994 <tytso@rsx-11.mit.edu>
* serial.c (rs_ioctl): Don't allow most ioctl's if the serial port
isn't initialized.
* serial.c (rs_close): Don't clear the IER if the serial port
isn't initialized.
* serial.c (block_til_ready): Don't try to block on the dialin
port if the serial port isn't initialized.
Wed Dec 7 10:48:30 1994 Si Park (si@wimpol.demon.co.uk)
* tty_io.c (tty_register_driver): Fix bug when linking onto
the tty_drivers list. We now test that there are elements
already on the list before setting the back link from the
first element to the new driver.
* tty_io.c (tty_unregister_driver): Fix bug in unlinking the
specified driver from the tty_drivers list. We were not
setting the back link correctly. This used to result in
a dangling back link pointer and cause panics on the next
call to get_tty_driver().
Tue Nov 29 10:21:09 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (tty_unregister_driver): Fix bug in
tty_unregister_driver where the pointer to the refcount is
tested, instead of the refcount itself. This caused
tty_unregister_driver to always return EBUSY.
Sat Nov 26 11:59:24 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (tty_ioctl): Add support for the new ioctl
TIOCTTYGSTRUCT, which allow a kernel debugging program
direct read access to the tty and tty_driver structures.
Fri Nov 25 17:26:22 1994 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_set_termios): Don't wake up processes blocked in
open when the CLOCAL flag changes, since a blocking
open only samples the CLOCAL flag once when it blocks,
and doesn't check it again. (n.b. FreeBSD has a
different behavior for blocking opens; it's not clear
whether Linux or FreeBSD's interpretation is correct.
POSIX doesn't give clear guidance on this issue, so
this may change in the future....)
* serial.c (block_til_ready): Use the correct termios structure to
check the CLOCAL flag. If the cuaXX device is active,
then check the saved termios for the ttySXX device.
Otherwise, use the currently active termios structure.
Sun Nov 6 21:05:44 1994 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (change_speed): Add support for direct access of
57,600 and 115,200 bps.
Wed Nov 2 10:32:36 1994 Theodore Y. Ts'o (tytso@rt-11)
* n_tty.c (n_tty_receive_room): Only allow excess characters
through if we are in ICANON mode *and* there are other no
pending lines in the buffer. Otherwise cut and paste over
4k breaks.
Sat Oct 29 18:17:34 1994 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_ioctl, get_lsr_info): Added patch suggested by Arne
Riiber so that user mode programs can tell when the
transmitter shift register is empty.
Thu Oct 27 23:14:29 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_ioctl.c (wait_until_sent): Added debugging printk statements
(under the #ifdef TTY_DEBUG_WAIT_UNTIL_SENT)
* serial.c (rs_interrupt, rs_interrupt_single, receive_chars,
change_speed, rs_close): rs_close now disables receiver
interrupts when closing the serial port. This allows the
serial port to close quickly when Linux and a modem (or a
mouse) are engaged in an echo war; when closing the serial
port, we now first stop listening to incoming characters,
and *then* wait for the transmit buffer to drain.
In order to make this change, the info->read_status_mask
is now used to control what bits of the line status
register are looked at in the interrupt routine in all
cases; previously it was only used in receive_chars to
select a few of the status bits.
Mon Oct 24 23:36:21 1994 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_close): Add a timeout to the transmitter flush
loop; this is just a sanity check in case we have flaky
(or non-existent-but-configured-by-the-user) hardware.
Fri Oct 21 09:37:23 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (tty_fasync): When asynchronous I/O is enabled, if the
process or process group has not be specified yet, set it
to be the tty's process group, or if that is not yet set,
to the current process's pid.
Thu Oct 20 23:17:28 1994 Theodore Y. Ts'o (tytso@rt-11)
* n_tty.c (n_tty_receive_room): If we are doing input
canonicalization, let as many characters through as
possible, so that the excess characters can be "beeped".
Tue Oct 18 10:02:43 1994 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_start): Removed an incorrect '!' that was
preventing transmit interrupts from being re-enabled in
rs_start(). Fortunately in most cases it would be
re-enabled elsewhere, but this still should be fixed
correctly.
Sun Oct 9 23:46:03 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (do_tty_hangup): If the tty driver flags
TTY_DRIVER_RESET_TERMIOS is set, then reset the termios
settings back to the driver's initial configuration. This
allows the termios settings to be reset even if a process
has hung up file descriptors keeping a pty's termios from
being freed and reset.
* tty_io.c (release_dev): Fix memory leak. The pty's other
termios structure should also be freed.
* serial.c (rs_close, shutdown): Change how we wait for the
transmitter to completely drain before shutting down the
serial port. We now do it by scheduling in another
process instead of busy looping with the interrupts turned
on. This may eliminate some race condition problems that
some people seem to be reporting.
Sun Sep 25 14:18:14 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (release_dev): When freeing a tty make sure that both
the tty and the o_tty (if present) aren't a process's
controlling tty. (Previously, we only checked the tty.)
* serial.c (change_speed): Only enable the Modem Status
Interrupt for a port if CLOCAL is not set or CRTSCTS
is set. If we're not checking the carrier detect and
CTS line, there's no point in enabling the modem
status interrupt. This will save spurious interrupts
from slowing down systems who have terminals that
don't support either line. (Of course, if you want
only one of CD and CTS support, you will need a
properly wired serial cable.)
Thu Sep 22 08:32:48 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (do_SAK): Return if tty is null.
* tty_io.c (_tty_name): Return "NULL tty" if the passed in tty is
NULL.
Sat Sep 17 13:19:25 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_ioctl.c (n_tty_ioctl): Fix TIOCGLCKTRMIOS and
TIOCSLCKTRMIOS, which were totally broken. Remove
extra indirection from argument; it should be a struct
termios *, not a struct termios **.
&real_tty->termios_locked should have been
real_tty->termios_locked. This caused us to be
reading and writing the termios_locked structure to
random places in kernel memory.
* tty_io.c (release_dev): Oops! Forgot to delete a critical kfree
of the locked_termios. This leaves the locked_termios
structure pointed at a freed object.
Fri Sep 16 08:13:25 1994 Theodore Y. Ts'o (tytso@rt-11)
* tty_io.c (tty_open): Don't check for an exclusive open until
after the device specific open routine has been called.
Otherwise, the serial device ref counting will be screwed
up.
* serial.c (rs_open, block_til_ready): Don't set termios structure
until after block_til_ready has returned successfully.
Modify block_til_ready to check the normal_termios
structure directly, so it doesn't rely on termios being
set before it's called.
Thu Sep 15 23:34:01 1994 Theodore Y. Ts'o (tytso@rt-11)
* serial.c (rs_close): Turn off interrupts during rs_close() to
prevent a race condition with the hangup code (which
runs during a software interrupt).
* tty_io.c (release_dev): Don't free the locked_termios structure;
its state must be retained across device opens.
* tty_io.c (tty_unregister_driver): Added function to unregister a
tty driver. (For loadable device drivers.)
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