1 1998-08-26 Theodore Ts'o <tytso@rsts-11.mit.edu>
3 * serial.c (rs_open): Correctly decrement the module in-use count
6 Thu Feb 19 14:24:08 1998 Theodore Ts'o <tytso@rsts-11.mit.edu>
8 * tty_io.c (tty_name): Remove the non-reentrant (and non-SMP safe)
9 version of tty_name, and rename the reentrant _tty_name
10 function to be tty_name.
11 (tty_open): Add a warning message stating callout devices
14 Mon Dec 1 08:24:15 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
16 * tty_io.c (tty_get_baud_rate): Print a warning syslog if the
17 tty->alt_speed kludge is used; this means the system is
18 using the deprecated SPD_HI ioctls.
20 Mon Nov 24 10:37:49 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
22 * serial.c, esp.c, rocket.c: Change drivers to take advantage of
25 * tty_io.c (tty_get_baud_rate): New function which computes the
26 correct baud rate for the tty. More factoring out of
27 common code out of the serial driver to the high-level tty
30 Sat Nov 22 07:53:36 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
32 * serial.c, esp.c, rocket.c: Add tty->driver.break() routine, and
33 allow high-level tty code to handle the break and soft
36 * tty_ioctl.c (n_tty_ioctl): Support TIOCGSOFTCAR and
37 TIOCSSOFTCAR, so that device drivers don't have to support
40 * serial.c (autoconfig): Change 16750 test to hopefully eliminate
41 false results by people with strange 16550As being
42 detected as 16750s. Hopefully 16750s will still be
43 detected as 16750, and other weird UARTs won't get poorly
44 autodetected. If this doesn't work, I'll have to disable
45 the auto identification for the 16750.
47 * tty_io.c (tty_hangup): Now actually do the tty hangup
48 processing during the timer processing, and disable
49 interrupts while doing the hangup processing. This avoids
50 several nasty race conditions which happened when the
51 hangup processing was done asynchronously.
52 (tty_ioctl): Do break handling in the tty driver if
53 driver's break function is supported.
54 (tty_flip_buffer_push): New exported function which should
55 be used by drivers to push characters in the flip buffer
56 to the tty handler. This may either be done using a task
57 queue function for better CPU efficiency, or directly for
58 low latency operation.
60 * serial.c (rs_set_termios): Fix bug rs_set_termios when
61 transitioning away from B0, submitted by Stanislav
64 Thu Jun 19 20:05:58 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
66 * serial.c (begin_break, end_break, rs_ioctl): Applied patch
67 to support BSD ioctls to set and clear the break
70 * console.c (scrup, scrdown, insert_line, delete_line): Applied
71 fix suggested by Aaron Tiensivu to speed up block scrolls
74 * n_tty.c (opost_block, write_chan): Added a modified "fast
75 console" patch which processes a block of text via
76 "cooking" efficiently.
78 Wed Jun 18 15:25:50 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
80 * tty_io.c (init_dev, release_dev): Applied fix suggested by Bill
81 Hawes to prevent race conditions in the tty code.
83 * n_tty.c (n_tty_chars_in_buffer): Applied fix suggested by Bill
84 Hawes so that n_tty_chars_in_buffer returns the correct
85 value in the case when the tty is in cannonical mode. (To
86 avoid a pty deadlock with telnetd.)
88 Thu Feb 27 01:53:08 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
90 * serial.c (change_speed): Add support for the termios flag
91 CMSPAR, which allows the user to select stick parity.
92 (i.e, if PARODD is set, the parity bit is always 1; if
93 PARRODD is not set, then the parity bit is always 0).
95 Wed Feb 26 19:03:10 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
97 * serial.c (cleanup_module): Fix memory leak when using the serial
98 driver as a module; make sure tmp_buf gets freed!
100 Tue Feb 25 11:01:59 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
102 * serial.c (set_modem_info): Add support for setting and clearing
103 the OUT1 and OUT2 bits. (For special case UART's, usually
105 (autoconfig, change_speed): Fix TI 16750 support.
107 Sun Feb 16 00:14:43 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
109 * tty_io.c (release_dev): Add sanity check to make sure there are
110 no waiters on tty->read_wait or tty->write_wait.
112 * serial.c (rs_init): Don't autoconfig a device if the I/O region
115 * serial.c (serial_proc_info): Add support for /proc/serial.
117 Thu Feb 13 00:49:10 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
119 * serial.c (receive_chars): When the UART repotrs an overrun
120 condition, it does so with a valid character. Changed to
121 not throw away the valid character, but instead report the
122 overrun after the valid character.
124 * serial.c: Added new #ifdef's for some of the advanced serial
125 driver features. A minimal driver that only supports COM
126 1/2/3/4 without sharing serial interrupts only takes 17k;
127 the full driver takes 32k.
129 Wed Feb 12 14:50:44 1997 Theodore Ts'o <tytso@rsts-11.mit.edu>
134 * serial.c: Update routines to use the new 2.1 memory access
137 Wed Dec 4 07:51:52 1996 Theodore Ts'o <tytso@localhost.mit.edu>
139 * serial.c (change_speed): Use save_flags(); cli() and
140 restore_flags() in order to ensure we don't accidentally
141 turn on interrupts when starting up the port.
142 (startup): Move the insertion of serial structure into the
143 IRQ chain earlier into the startup processing. Interrupts
144 should be off this whole time, but we eventually will want
145 to reduce this window.
147 Thu Nov 21 10:05:22 1996 Theodore Ts'o <tytso@localhost.mit.edu>
149 * tty_ioctl.c (tty_wait_until_sent): Always check the driver
150 wait_until_ready routine, even if there are no characters
151 in the xmit buffer. (There may be charactes in the device
153 (n_tty_ioctl): Add new flag tty->flow_stopped which
154 indicates whether the tty is stopped due to a request by
155 the TCXONC ioctl (used by tcflow). If so, don't let an
156 incoming XOFF character restart the tty. The tty can only
157 be restarted by another TCXONC request.
159 * tty_io.c (start_tty): Don't allow the tty to be restarted if
160 tty->flow_stopped is true.
162 * n_tty.c (n_tty_receive_char): If tty->flow_stopped is true, and
163 IXANY is set, don't eat a character trying to restart the
166 * serial.c (startup): Remove need for MCR_noint from the
167 async_struct structure. Only turn on DTR and RTS if the
168 baud rate is not zero.
169 (change_speed): More accurately calculate the timeout
170 value based on the word size. Move responsibility of
171 hangup when speed becomes B0 to rs_set_termios()
172 (set_serial_info): When changing the UART type set the
173 current xmit_fifo_size as well as the permanent
175 (rs_ioctl): Fix TCSBRK (used by tcdrain) and TCSBRKP
176 ioctls to return EINTR if interrupted by a signal.
177 (rs_set_termios): If the baud rate changes to or from B0,
178 this function is now responsible for setting or clearing
179 DTR and RTS. DTR and RTS are only be changed on the
180 transition to or from the B0 state.
181 (rs_close): Wait for the characters to drain based on
182 info->timeout. At low baud rates (50 bps), it may take a
183 long time for the FIFO to completely drain out!
184 (rs_wait_until_sent): Fixed timeout handling. Now
185 releases control to the scheduler, but checks frequently
186 enough so that the function is sensitive enough to pass
187 the timing requirements of the NIST-PCTS.
188 (block_til_ready): When opening the device, don't turn on
189 DTR and RTS if the baud rate is B0.
191 Thu Nov 14 00:06:09 1996 Theodore Ts'o <tytso@rsts-11.mit.edu>
193 * serial.c (autoconfig): Fix autoconfiguration problems;
194 info->flags wasn't getting initialized from the state
195 structure. Put in more paranoid test for the 16750.
197 Fri Nov 8 20:19:50 1996 Theodore Ts'o <tytso@rsts-11.mit.edu>
199 * n_tty.c (n_tty_flush_buffer): Only call driver->unthrottle() if
200 the tty was previous throttled.
201 (n_tty_set_termios, write_chan): Add changes suggested by
202 Simon P. Allen to allow hardware cooking.
204 * tty_ioctl.c (set_termios): If we get a signal while waiting for
205 the tty to drain, return -EINTR.
207 * serial.c (change_speed): Add support for CREAD, as required by
210 Sat Nov 2 20:43:10 1996 Theodore Ts'o <tytso@rsts-11.mit.edu>
212 * serial.c: Wholesale changes. Added support for the Startech
213 16650 and 16650V2 chips. (WARNING: the new startech
214 16650A may or may not work!) Added support for the
215 TI16750 (not yet tested). Split async_struct into a
216 transient part (async_struct) and a permanent part
217 (serial_state) which contains the configuration
218 information for the ports. Added new driver routines
219 wait_until_sent() and send_xchar() to help with POSIX
220 compliance. Added support for radio clocks which waggle
221 the carrier detect line (CONFIG_HARD_PPS).
223 * tty_ioctl.c (tty_wait_until_sent): Added call to new driver
224 function tty->driver.wait_until_sent(), which returns when
225 the tty's device xmit buffers are drained. Needed for
226 full POSIX compliance.
228 (send_prio_char): New function, called by the ioctl's
229 TCIOFF and TCION; uses the new driver call send_xchar(),
230 which will send the XON or XOFF character at high priority
231 (and even if tty output is stopped).
233 Wed Jun 5 18:52:04 1996 Theodore Ts'o <tytso@rsts-11.mit.edu>
235 * pty.c (pty_close): When closing a pty, make sure packet mode is
238 Sun May 26 09:33:52 1996 Theodore Ts'o <tytso@rsts-11.mit.edu>
240 * vesa_blank.c (set_vesa_blanking): Add missing verify_area() call.
242 * selection.c (set_selection): Add missing verify_area() call.
244 * tty_io.c (tty_ioctl): Add missing verify_area() calls.
246 * serial.c (rs_ioctl): Add missing verify_area() calls.
247 (rs_init): Allow initialization of serial driver
248 configuration from a module.
250 * random.c (extract_entropy): Add missing verify_area call.
251 Don't limit number of characters returned to
252 32,768. Extract entropy is now no longer a inlined
255 (random_read): Check return value in case extract_entropy
258 (secure_tcp_sequence_number): New function which returns a
259 secure TCP sequence number. This is needed to prevent some
260 nasty TCP hijacking attacks.
262 (init_std_data): Initialize using gettimeofday() instead of
263 struct timeval xtime.
265 (fast_add_entropy_word, add_entropy_word): Rename the
266 inline function add_entropy_word() to
267 fast_add_entropy_word(). Make add_entropy_word() be the
268 non-inlined function which is used in non-timing critical
269 places, in order to save space.
271 (initialize_benchmark, begin_benchmark, end_benchmark): New
272 functions defined when RANDOM_BENCHMARK is defined. They
273 allow us to benchmark the speed of the
274 add_timer_randomness() call.
276 (int_ln, rotate_left): Add two new inline functions with
277 i386 optimized asm instructions. This speeds up the
278 critical add_entropy_word() and add_timer_randomness()
279 functions, which are called from interrupt handlers.
281 Tue May 7 22:51:11 1996 <tytso@rsts-11.mit.edu>
283 * random.c (add_timer_randomness): Limit the amount randomness
284 that we estimate to 12 bits. (An arbitrary amount).
286 (extract_entropy): To make it harder to analyze the hash
287 function, fold the hash function in half using XOR, and
288 use the folded result as the value to emit to the user.
289 Also, add timer randomness each pass through the
290 exact_entropy call, to increase the amount of unknown
291 values during the extraction process.
293 (random_ioctl): Use IOR/IOW definitions to define the
294 ioctl values used by the /dev/random driver. Allow the
295 old ioctl values to be used for backwards compatibility
296 (for a limited amount of time).
298 Wed Apr 24 14:02:04 1996 Theodore Ts'o <tytso@rsts-11.mit.edu>
300 * random.c (add_timer_randomness): Use 2nd derivative as well to
301 better estimate entropy.
303 (rand_initialize): Explicitly initialize all the pointers
304 to NULL. (Clearing pointers using memset isn't portable.)
305 Initialize the random pool with OS-dependent data.
307 (random_write): Add sanity checking to the arguments to
308 random_write(), so that bad arguments won't cause a kernel
311 (random_read): Update the access time of the device inode
312 when you return data to the user.
314 (random_ioctl): Wake up the random_wait channel when there
315 are only WAIT_INPUT_BITS available. Add more paranoia
316 checks to make sure entropy_count doesn't go beyond the
317 bounds of (0, POOLSIZE). Add a few missing verify_area
318 checks. Add support for the RNDCLEARPOOL ioctl, which
319 zaps the random pool.
321 (add_timer_randomness): Wake up the random_wait
322 channel only when there are WAIT_INPUT_BITS available.
324 (random_select): Allow a random refresh daemon process to
325 select on /dev/random for writing; wake up the daemon when
326 there are less than WAIT_OUTPUT_BITS bits of randomness
329 Tue Apr 23 22:56:07 1996 <tytso@rsts-11.mit.edu>
331 * tty_io.c (init_dev): Change return code when user attempts to
332 open master pty which is already open from EAGAIN to EIO,
333 to match with BSD expectations. EIO is more correct
334 anyway, since EAGAIN implies that retrying will be
335 successful --- which it might be.... Eventually!!
337 * pty.c (pty_open, pty_close): Fix wait loop so that we don't
338 busy loop while waiting for the master side to open.
339 Fix tty opening/closing logic. TTY_SLAVE_CLOSED was
340 renamed to TTY_OTHER_CLOSED, so that the name is more
341 descriptive. Also fixed code so that the tty flag
342 actually works correctly now....
344 Mon Apr 1 10:22:01 1996 <tytso@rsts-11.mit.edu>
346 * serial.c (rs_close): Cleaned up modularization changes.
347 Remove code which forced line discipline back to N_TTY
348 this is done in the tty upper layers, and there's no
349 reason to do it here. (Making this change also
350 removed the requirement that the serial module access
351 the internal kernel symbol "ldiscs".)
353 * tty_io.c (tty_init): Formally register a tty_driver entry for
354 /dev/tty (device 4, 0) and /dev/console (device 5, 0).
355 This guarantees that major device numbers 4 and 5 will be
356 reserved for the tty subsystem (as they have to be because
357 of /dev/tty and /dev/console). Removed tty_regdev, as
358 this interface is no longer necessary.
360 Sun Mar 17 20:42:47 GMT 1996 <ah@doc.ic.ac.uk>
362 * serial.c : modularisation (changes in linux/fs/device.c allow
363 kerneld to automatically load the serial module).
365 * Makefile, Config.in : serial modularisation adds.
367 * tty_io.c : tty_init_ctty used by to register "cua" driver just
368 for the /dev/tty device (5,0). Added tty_regdev.
370 * serial.c (shutdown, rs_ioctl) : when port shuts down wakeup processes
371 waiting on delta_msr_wait. The TIOCMIWAIT ioctl returns EIO
372 if no change was done since the time of call.
374 Sat Mar 16 14:33:13 1996 <aeb@cwi.nl>
376 * tty_io.c (disassociate_ctty): If disassociate_ctty is called by
377 exit, do not perform an implicit vhangup on a pty.
379 Fri Feb 9 14:15:47 1996 <tytso@rsts-11.mit.edu>
381 * serial.c (block_til_ready): Fixed another race condition which
382 happens if a hangup happens during the open.
384 Wed Jan 10 10:08:00 1996 <tytso@rsts-11.mit.edu>
386 * serial.c (block_til_ready): Remove race condition which happened
387 if a hangup condition happened during the setup of the
388 UART, before rs_open() called block_til_ready(). This
389 caused the info->count counter to be erroneously
392 * serial.c (startup, rs_open): Remove race condition that could
393 cause a memory leak of one page. (Fortunately, both race
394 conditions were relatively rare in practice.)
396 Tue Dec 5 13:21:27 1995 <tytso@rsts-11.mit.edu>
398 * serial.c (check_modem_status, rs_ioctl): Support the new
399 ioctl()'s TIOCGICOUNT, TIOCMIWAIT. These allow an
400 application program to wait on a modem serial register
401 status bit change, and to find out how many changes have
402 taken place for the MSR bits.
404 (rs_write): Eliminate a race condition which is introduced
405 if it is necessary to wait for the semaphore.
407 Sat Nov 4 17:14:45 1995 <tytso@rsts-11.mit.edu>
409 * tty_io.c (tty_init): Move registration of TTY_MAJOR and
410 TTY_AUX_MAJOR to the end, so that /proc/devices looks
413 * pty.c (pty_init): Use new major numbers for PTY master and slave
414 devices. This allow us to have more than 64 pty's. We
415 register the old pty devices for backwards compatibility.
416 Note that a system should either be using the old pty
417 devices or the new pty devices --- in general, it should
418 try to use both, since they map into the same pty table.
419 The old pty devices are strictly for backwards compatibility.
421 Wed Oct 11 12:45:24 1995 <tytso@rsts-11.mit.edu>
423 * tty_io.c (disassociate_ctty): If disassociate_ctty is called by
424 exit, perform an implicit vhangup on the tty.
426 * pty.c (pty_close): When the master pty is closed, send a hangup
428 (pty_open): Use the flag TTY_SLAVE_CLOSED to test to see
429 if there are any open slave ptys, instead of using
430 tty->link->count. The old method got confused if there
431 were processes that had hung-up file descriptors on the
434 Tue May 2 00:53:25 1995 <tytso@rsx-11.mit.edu>
436 * tty_io.c (tty_set_ldisc): Wait until the output buffer is
437 drained before closing the old line discipline --- needed
438 in only one case: XON/XOFF processing.
440 * n_tty.c (n_tty_close): Don't bother waiting until the output
441 driver is closed; in general, the line discipline
442 shouldn't care if the hardware is finished
443 transmitting before the line discipline terminates.
445 * tty_io.c (release_dev): Shutdown the line discipline after
446 decrementing the tty count variable; but set the
447 TTY_CLOSING flag so that we know that this tty structure
448 isn't long for this world.
450 * tty_io.c (init_dev): Add sanity code to check to see if
451 TTY_CLOSING is set on a tty structure; if so, something
452 bad has happened (probably a line discipline close blocked
453 when it shouldn't have; so do a kernel printk and then
456 Wed Apr 26 10:23:44 1995 Theodore Y. Ts'o <tytso@localhost>
458 * tty_io.c (release_dev): Try to shutdown the line discipline
459 *before* decrementing the tty count variable; this removes
460 a potential race condition which occurs when the line
461 discipline close blocks, and another process then tries
462 open the same serial port.
464 * serial.c (rs_hangup): When hanging up, flush the output buffer
465 before shutting down the UART. Otherwise the line
466 discipline close blocks waiting for the characters to get
467 flushed, which never happens until the serial port gets reused.
469 Wed Apr 12 08:06:16 1995 Theodore Y. Ts'o <tytso@localhost>
471 * serial.c (do_serial_hangup, do_softint, check_modem_status,
472 rs_init): Hangups are now scheduled via a separate tqueue
473 structure in the async_struct structure, tqueue_hangup.
474 This task is pushed on to the tq_schedule queue, so that
475 it is processed synchronously by the scheduler.
477 Sat Feb 18 12:13:51 1995 Theodore Y. Ts'o (tytso@rt-11)
479 * tty_io.c (disassociate_ctty, tty_open, tty_ioctl): Clear
480 current->tty_old_pgrp field when a session leader
481 acquires a controlling tty, and after a session leader
482 has disassociated from a controlling tty.
484 Fri Feb 17 09:34:09 1995 Theodore Y. Ts'o (tytso@rt-11)
486 * serial.c (rs_interrupt_single, rs_interrupt, rs_interrupt_multi):
487 Change the number of passes made from 64 to be 256,
488 configurable with the #define RS_ISR_PASS_LIMIT.
490 * serial.c (rs_init, set_serial_info, get_serial_info, rs_close):
491 Remove support for closing_wait2. Instead, set
492 tty->closing and rely on the line discipline to prevent
495 * n_tty.c (n_tty_receive_char): IEXTEN does not need to be
496 enabled in order for IXANY to be active.
498 If tty->closing is set, then only process XON and XOFF
501 Sun Feb 12 23:57:48 1995 Theodore Y. Ts'o (tytso@rt-11)
503 * serial.c (rs_timer): Change the interrupt poll time from 60
504 seconds to 10 seconds, configurable with the #define
507 * serial.c (rs_interrupt_multi, startup, shutdown, rs_ioctl,
508 set_multiport_struct, get_multiport_struct): Add
509 provisions for a new type of interrupt service routine,
510 which better supports multiple serial ports on a single
513 Sun Feb 5 19:35:11 1995 Theodore Y. Ts'o (tytso@rt-11)
515 * tty_ioctl.c (n_tty_ioctl, set_termios, tty_wait_until_sent):
516 * serial.c (rs_ioctl, rs_close):
517 * cyclades.c (cy_ioctl, cy_close):
518 * n_tty.c (n_tty_close): Rename wait_until_sent to
519 tty_wait_until_sent, so that it's a better name to export
522 Sat Feb 4 23:36:20 1995 Theodore Y. Ts'o (tytso@rt-11)
524 * serial.c (rs_close): Added missing check for closing_wait2 being
525 ASYNC_CLOSING_WAIT_NONE.
527 Thu Jan 26 09:02:49 1995 Theodore Y. Ts'o (tytso@rt-11)
529 * serial.c (rs_init, set_serial_info, get_serial_info,
530 rs_close): Support close_wait in the serial driver.
531 This is helpful for slow devices (like serial
532 plotters) so that their outputs don't get flushed upon
533 device close. This has to be configurable because
534 normally we don't want ports to be hung up for long
535 periods of time during a close when they are not
536 connected to a device, or the device is powered off.
538 The default is to wait 30 seconds; in the case of a
539 very slow device, the close_wait timeout should be
540 lengthened. If it is set to 0, the kernel will wait
541 forever for all of the data to be transmitted.
543 Thu Jan 17 01:17:20 1995 Theodore Y. Ts'o (tytso@rt-11)
545 * serial.c (startup, change_speed, rs_init): Add support to detect
546 the StarTech 16650 chip. Treat it as a 16450 for now,
547 because of its FIFO bugs.
549 Thu Jan 5 21:21:57 1995 <dhinds@allegro.stanford.edu>
551 * serial.c: (receive_char): Added counter to prevent infinite loop
552 when a PCMCIA serial device is ejected.
554 Thu Dec 29 17:53:48 1994 <tytso@rsx-11.mit.edu>
556 * tty_io.c (check_tty_count): New procedure which checks
557 tty->count to make sure that it matches with the number of
558 open file descriptors which point at the structure. If
559 the number doesn't match, it prints a warning message.
561 Wed Dec 28 15:41:51 1994 <tytso@rsx-11.mit.edu>
563 * tty_io.c (do_tty_hangup, disassociate_ctty): At hangup time,
564 save the tty's current foreground process group in the
565 session leader's task structure. When the session leader
566 terminates, send a SIGHUP, SIGCONT to that process group.
567 This is not required by POSIX, but it's not prohibited
568 either, and it appears to be the least intrusive way
569 to fix a problem that dialup servers have with
570 orphaned process groups caused by modem hangups.
572 Thu Dec 8 14:52:11 1994 <tytso@rsx-11.mit.edu>
574 * serial.c (rs_ioctl): Don't allow most ioctl's if the serial port
577 * serial.c (rs_close): Don't clear the IER if the serial port
580 * serial.c (block_til_ready): Don't try to block on the dialin
581 port if the serial port isn't initialized.
583 Wed Dec 7 10:48:30 1994 Si Park (si@wimpol.demon.co.uk)
584 * tty_io.c (tty_register_driver): Fix bug when linking onto
585 the tty_drivers list. We now test that there are elements
586 already on the list before setting the back link from the
587 first element to the new driver.
589 * tty_io.c (tty_unregister_driver): Fix bug in unlinking the
590 specified driver from the tty_drivers list. We were not
591 setting the back link correctly. This used to result in
592 a dangling back link pointer and cause panics on the next
593 call to get_tty_driver().
595 Tue Nov 29 10:21:09 1994 Theodore Y. Ts'o (tytso@rt-11)
597 * tty_io.c (tty_unregister_driver): Fix bug in
598 tty_unregister_driver where the pointer to the refcount is
599 tested, instead of the refcount itself. This caused
600 tty_unregister_driver to always return EBUSY.
602 Sat Nov 26 11:59:24 1994 Theodore Y. Ts'o (tytso@rt-11)
604 * tty_io.c (tty_ioctl): Add support for the new ioctl
605 TIOCTTYGSTRUCT, which allow a kernel debugging program
606 direct read access to the tty and tty_driver structures.
608 Fri Nov 25 17:26:22 1994 Theodore Y. Ts'o (tytso@rt-11)
610 * serial.c (rs_set_termios): Don't wake up processes blocked in
611 open when the CLOCAL flag changes, since a blocking
612 open only samples the CLOCAL flag once when it blocks,
613 and doesn't check it again. (n.b. FreeBSD has a
614 different behavior for blocking opens; it's not clear
615 whether Linux or FreeBSD's interpretation is correct.
616 POSIX doesn't give clear guidance on this issue, so
617 this may change in the future....)
619 * serial.c (block_til_ready): Use the correct termios structure to
620 check the CLOCAL flag. If the cuaXX device is active,
621 then check the saved termios for the ttySXX device.
622 Otherwise, use the currently active termios structure.
624 Sun Nov 6 21:05:44 1994 Theodore Y. Ts'o (tytso@rt-11)
626 * serial.c (change_speed): Add support for direct access of
627 57,600 and 115,200 bps.
629 Wed Nov 2 10:32:36 1994 Theodore Y. Ts'o (tytso@rt-11)
631 * n_tty.c (n_tty_receive_room): Only allow excess characters
632 through if we are in ICANON mode *and* there are other no
633 pending lines in the buffer. Otherwise cut and paste over
636 Sat Oct 29 18:17:34 1994 Theodore Y. Ts'o (tytso@rt-11)
638 * serial.c (rs_ioctl, get_lsr_info): Added patch suggested by Arne
639 Riiber so that user mode programs can tell when the
640 transmitter shift register is empty.
642 Thu Oct 27 23:14:29 1994 Theodore Y. Ts'o (tytso@rt-11)
644 * tty_ioctl.c (wait_until_sent): Added debugging printk statements
645 (under the #ifdef TTY_DEBUG_WAIT_UNTIL_SENT)
647 * serial.c (rs_interrupt, rs_interrupt_single, receive_chars,
648 change_speed, rs_close): rs_close now disables receiver
649 interrupts when closing the serial port. This allows the
650 serial port to close quickly when Linux and a modem (or a
651 mouse) are engaged in an echo war; when closing the serial
652 port, we now first stop listening to incoming characters,
653 and *then* wait for the transmit buffer to drain.
655 In order to make this change, the info->read_status_mask
656 is now used to control what bits of the line status
657 register are looked at in the interrupt routine in all
658 cases; previously it was only used in receive_chars to
659 select a few of the status bits.
661 Mon Oct 24 23:36:21 1994 Theodore Y. Ts'o (tytso@rt-11)
663 * serial.c (rs_close): Add a timeout to the transmitter flush
664 loop; this is just a sanity check in case we have flaky
665 (or non-existent-but-configured-by-the-user) hardware.
667 Fri Oct 21 09:37:23 1994 Theodore Y. Ts'o (tytso@rt-11)
669 * tty_io.c (tty_fasync): When asynchronous I/O is enabled, if the
670 process or process group has not be specified yet, set it
671 to be the tty's process group, or if that is not yet set,
672 to the current process's pid.
674 Thu Oct 20 23:17:28 1994 Theodore Y. Ts'o (tytso@rt-11)
676 * n_tty.c (n_tty_receive_room): If we are doing input
677 canonicalization, let as many characters through as
678 possible, so that the excess characters can be "beeped".
680 Tue Oct 18 10:02:43 1994 Theodore Y. Ts'o (tytso@rt-11)
682 * serial.c (rs_start): Removed an incorrect '!' that was
683 preventing transmit interrupts from being re-enabled in
684 rs_start(). Fortunately in most cases it would be
685 re-enabled elsewhere, but this still should be fixed
688 Sun Oct 9 23:46:03 1994 Theodore Y. Ts'o (tytso@rt-11)
690 * tty_io.c (do_tty_hangup): If the tty driver flags
691 TTY_DRIVER_RESET_TERMIOS is set, then reset the termios
692 settings back to the driver's initial configuration. This
693 allows the termios settings to be reset even if a process
694 has hung up file descriptors keeping a pty's termios from
695 being freed and reset.
697 * tty_io.c (release_dev): Fix memory leak. The pty's other
698 termios structure should also be freed.
700 * serial.c (rs_close, shutdown): Change how we wait for the
701 transmitter to completely drain before shutting down the
702 serial port. We now do it by scheduling in another
703 process instead of busy looping with the interrupts turned
704 on. This may eliminate some race condition problems that
705 some people seem to be reporting.
707 Sun Sep 25 14:18:14 1994 Theodore Y. Ts'o (tytso@rt-11)
709 * tty_io.c (release_dev): When freeing a tty make sure that both
710 the tty and the o_tty (if present) aren't a process's
711 controlling tty. (Previously, we only checked the tty.)
713 * serial.c (change_speed): Only enable the Modem Status
714 Interrupt for a port if CLOCAL is not set or CRTSCTS
715 is set. If we're not checking the carrier detect and
716 CTS line, there's no point in enabling the modem
717 status interrupt. This will save spurious interrupts
718 from slowing down systems who have terminals that
719 don't support either line. (Of course, if you want
720 only one of CD and CTS support, you will need a
721 properly wired serial cable.)
723 Thu Sep 22 08:32:48 1994 Theodore Y. Ts'o (tytso@rt-11)
725 * tty_io.c (do_SAK): Return if tty is null.
727 * tty_io.c (_tty_name): Return "NULL tty" if the passed in tty is
730 Sat Sep 17 13:19:25 1994 Theodore Y. Ts'o (tytso@rt-11)
732 * tty_ioctl.c (n_tty_ioctl): Fix TIOCGLCKTRMIOS and
733 TIOCSLCKTRMIOS, which were totally broken. Remove
734 extra indirection from argument; it should be a struct
735 termios *, not a struct termios **.
736 &real_tty->termios_locked should have been
737 real_tty->termios_locked. This caused us to be
738 reading and writing the termios_locked structure to
739 random places in kernel memory.
741 * tty_io.c (release_dev): Oops! Forgot to delete a critical kfree
742 of the locked_termios. This leaves the locked_termios
743 structure pointed at a freed object.
745 Fri Sep 16 08:13:25 1994 Theodore Y. Ts'o (tytso@rt-11)
747 * tty_io.c (tty_open): Don't check for an exclusive open until
748 after the device specific open routine has been called.
749 Otherwise, the serial device ref counting will be screwed
752 * serial.c (rs_open, block_til_ready): Don't set termios structure
753 until after block_til_ready has returned successfully.
754 Modify block_til_ready to check the normal_termios
755 structure directly, so it doesn't rely on termios being
756 set before it's called.
758 Thu Sep 15 23:34:01 1994 Theodore Y. Ts'o (tytso@rt-11)
760 * serial.c (rs_close): Turn off interrupts during rs_close() to
761 prevent a race condition with the hangup code (which
762 runs during a software interrupt).
764 * tty_io.c (release_dev): Don't free the locked_termios structure;
765 its state must be retained across device opens.
768 * tty_io.c (tty_unregister_driver): Added function to unregister a
769 tty driver. (For loadable device drivers.)