Commit Graph

36 Commits

Author SHA1 Message Date
David S. Miller 9365f11a53 isdn: i4l: isdn_tty: Fix unused-but-set variables.
The variable 'fcr' is set but not used in isdn_tty_change_speed().

Just kill it off.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-17 17:07:57 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Alan Cox 6caa76b778 tty: now phase out the ioctl file pointer for good
Only oddities here are a couple of drivers that bogusly called the ldisc
helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes
away.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:59:56 -08:00
Alan Cox 20b9d17715 tiocmset: kill the file pointer argument
Doing tiocmget was such fun we should do tiocmset as well for the same
reasons

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:52:43 -08:00
Alan Cox 60b33c133c tiocmget: kill off the passing of the struct file
We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:47:33 -08:00
Arnd Bergmann 72250d44bc i4l: kill big kernel lock
The isdn4linux driver uses the big kernel lock only
to serialize access to a few fields in its own
modem_info structure.

The easiest replacement is a driver-wide mutex.
More fine-grained locking would be more appropriate
here, but likely harder to implement.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-15 19:29:55 -07:00
Dan Carpenter f417f5e4ba isdn: cleanup: make buffer smaller
This showed up in my audit because we use strcpy() to copy "ds" into a
32 character buffer inside the isdn_tty_dial() function.  But it turns
out that we only ever use the first 32 characters so it's OK.  I have
changed the declaration to make the static checkers happy.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-06 18:29:19 -07:00
Tilman Schmidt bc10f96757 isdn: avoid calling tty_ldisc_flush() in atomic context
Remove the call to tty_ldisc_flush() from the RESULT_NO_CARRIER
branch of isdn_tty_modem_result(), as already proposed in commit
00409bb045.
This avoids a "sleeping function called from invalid context" BUG
when the hardware driver calls the statcallb() callback with
command==ISDN_STAT_DHUP in atomic context, which in turn calls
isdn_tty_modem_result(RESULT_NO_CARRIER, ~), and from there,
tty_ldisc_flush() which may sleep.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-05 19:41:23 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Alexey Dobriyan 405f55712d headers: smp_lock.h redux
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00
Roel Kluin 395df11f5f drivers/isdn/i4l/isdn_tty.c: fix check for array overindexing
The check for overindexing of dev->mdm.info[] has an off-by-one.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Karsten Keil <keil@b1-systems.de>
2009-06-11 19:05:10 +02:00
Alan Cox 978e595f88 tty/serial: lay the foundations for the next set of reworks
- Stop drivers calling their own flush method indirectly, it obfuscates code
  and it will change soon anyway

- A few more lock_kernel paths temporarily needed in some driver internal
  waiting code

- Remove private put_char method that does a write call for one char - we
  have that anyway

- Most but not yet all of the termios copy under lock fixing (some has other
  dependencies to follow)

- Note a few locking bugs in drivers found in the process

- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
  fix the termios locking

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:45 -07:00
Alan Cox 6e4d376c66 isdn_tty: Prepare for BKL push down
Three things here
- Remove softcar handler
- Correct termios change detection logic
- Wrap break/ioctl in lock_kernel ready to drop it in the caller

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Harvey Harrison 156f1ed640 isdn: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:34 -07:00
Daniel Walker 4749380ed6 drivers/isdn/i4l/isdn_tty.c: remove write_sem
I couldn't find any users, so removing it..

Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:07 -08:00
Matthias Goebl 7fde4d779b [ISDN]: i4l: Fix DLE handling for i4l-audio
The DLE handling in i4l-audio seems to be broken.

It produces spurious DLEs so asterisk 1.2.24 with chan_modem_i4l
gets irritated, the error message is:
"chan_modem_i4l.c:450 i4l_read: Value of escape is ^ (17)".
-> There shouldn't be a DLE-^.
If a spurious DLE-ETX occurs, the audio connection even dies.
I use a "AVM Fritz!PCI" isdn card.

I found two issues that only appear if ISDN_AUDIO_SKB_DLECOUNT(skb) > 0:
- The loop in isdn_tty.c:isdn_tty_try_read() doesn't escape a DLE if it's
  the last character.

- The loop in isdn_common.c:isdn_readbchan_tty() doesn't copy its characters,
  it only remembers the last one ("last = *p;").

  Compare it with the loop in isdn_common.c:isdn_readbchan(), that *does*
  copy them ("*cp++ = *p;") correctly.
  The special handling of the "last" character made it more difficult.
  I compared it to linux-2.4.19: There was no "last"-handling and both loops
  did escape and copy all characters correctly.

Signed-off-by: Matthias Goebl <matthias.goebl@goebl.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-04 03:55:44 -08:00
Matthias Goebl 00409bb045 [ISDN] i4l: 'NO CARRIER' message lost after ldisc flush
The ISDN tty layer doesn't produce a 'NO CARRIER' message after hangup.

I suppose it broke when tty_buffer_flush() has been added to
tty_ldisc_flush() in the commit below.

For isdn_tty_modem_result(RESULT_NO_CARRIER..) the
message inserted via isdn_tty_at_cout() -> tty_insert_flip_char()
is flushed immediately by tty_ldisc_flush() -> tty_buffer_flush().
More annoyingly, the audio abort sequence DLE-ETX is also lost.

This patch fixes only active audio connections, because I assume that nobody
changes the line discipline for audio.

For non-audio connections the problem remains.
Maybe we can remove the tty_ldisc_flush() in isdn_tty_modem_result()
at all because it's done at tty_close?

On Mon, May 07, 2007 at 04:05:57PM -0500, Paul Fulghum wrote:
> Flush the tty flip buffer when the line discipline
> input queue is flushed, including the user call
> tcflush(TCIFLUSH/TCIOFLUSH). This prevents unexpected
> stale data after a user application calls tcflush().
>
> Cc: Alan Cox <alan@lxorguk.org.uk>
> Cc: Antonino Ingargiola <tritemio@gmail.com>
> Signed-off-by: Paul Fulghum <paulkf@microgate.com>
>
> --- a/drivers/char/tty_io.c	2007-05-04 05:46:55.000000000 -0500
> +++ b/drivers/char/tty_io.c	2007-05-05 03:23:46.000000000 -0500
> @@ -1240,6 +1263,7 @@ void tty_ldisc_flush(struct tty_struct *
>  			ld->flush_buffer(tty);
>  		tty_ldisc_deref(ld);
>  	}
> +	tty_buffer_flush(tty);
[..]

Signed-off-by: Matthias Goebl <matthias.goebl@goebl.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-04 03:55:40 -08:00
Karsten Keil 924ad15844 Fix broken CLIR in isdn driver
I noticed that CLIR (aka "hide your calling number") in isdn_tty is broken:
The at-command parser filters out the required "R" (e.g.  ATDR089123456)
It's been broken for a *very* long time.

Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Matthias Goebl <matthias.goebl@goebl.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:29 -07:00
Jiri Slaby b963a8441c [PATCH] Char: tty_wakeup cleanup
tty_wakeup cleanup

- remove wake_up_interruptible(&tty->write_wait) surrounding
  tty_wakup(tty);
- substitute tty->ldisc.write_wakeup(tty) + wake_up() by tty_wakeup(tty);

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:26 -08:00
Alan Cox 606d099cdd [PATCH] tty: switch to ktermios
This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:57 -08:00
Jeff Dike b68e31d0eb [PATCH] const struct tty_operations
As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking.  One of these
structures was a struct tty_operations.  In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.

This patch declares all struct tty_operations in the tree as const.  In all
cases, they are static and used only as input to tty_set_operations.  As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.

53 drivers are affected.  I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months.  serial_core.c was the busiest one that I looked at.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:14 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Linus Torvalds 602cada851 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6: (22 commits)
  [PATCH] devfs: Remove it from the feature_removal.txt file
  [PATCH] devfs: Last little devfs cleanups throughout the kernel tree.
  [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV
  [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the line_driver devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the videodevice devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the miscdevice devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree
  [PATCH] devfs: Remove devfs_remove() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_cdev() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_bdev() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_symlink() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree
  [PATCH] devfs: Remove devfs_*_tape() functions from the kernel tree
  [PATCH] devfs: Remove devfs support from the sound subsystem
  [PATCH] devfs: Remove devfs support from the ide subsystem.
  [PATCH] devfs: Remove devfs support from the serial subsystem
  [PATCH] devfs: Remove devfs from the init code
  [PATCH] devfs: Remove devfs from the partition code
  ...
2006-06-29 14:19:21 -07:00
Karsten Keil ca6f8792bd [PATCH] i4l fix DLE masking in isdn_tty_try_read
DLE masking was non-functional since the new tty handling.

Found by Peter Evertz <leo2@pec.homeip.net>

Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:00:36 -07:00
Greg Kroah-Hartman 331b831983 [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV
I've always found this flag confusing.  Now that devfs is no longer around, it
has been renamed, and the documentation for when this flag should be used has
been updated.

Also fixes all drivers that use this flag.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:09 -07:00
Greg Kroah-Hartman f4eaa37017 [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed
Also fixes all drivers that set this field.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:09 -07:00
Eric Sesterhenn a6a61c5494 [PATCH] Overrun in isdn_tty.c
This fixes coverity bug id #1237.  After the while loop, it is possible for
i == ISDN_LMSNLEN.  If this happens the terminating '\0' is written after
the end of the array.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:18 -07:00
Adrian Bunk 1f4d4a80fb [PATCH] i4l/isdn_tty.c: fix a check-after-use
Fix a check-after-use spotted by the Coverity checker.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:59 -08:00
Karsten Keil 7cb9478f0d [PATCH] i4l: fix refcounting problem with ttyIx devices
If the same ttyIx device was opened by two processes the module was not
released and so the usage count went never to zero again.  This oneliner fixes
the issue.

Signed-off-by: Oskar Senft <o.senft@sirrix.com>
Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06 18:40:43 -08:00
Karsten Keil 61b9a26ae6 [PATCH] Fix NULL pointer dereference in isdn_tty_at_cout
The changes in the tty related code introduced wrong parenthesis in a if
condition in the isdn_tty_at_cout function.  This caused access to index -1
in the dev->drv[] array.  This patch change it back to the correct
condition from the previous versions.

Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14 16:09:34 -08:00
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00
Jesper Juhl 3c7208f253 [PATCH] kfree cleanup: drivers/isdn
This is the drivers/isdn/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in drivers/isdn/.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:54:02 -08:00
Nishanth Aravamudan 24763c48a3 [PATCH] isdn: fix-up schedule_timeout() usage
Use schedule_timeout_interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:57 -08:00
David S. Miller b03efcfb21 [NET]: Transform skb_queue_len() binary tests into skb_queue_empty()
This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-08 14:57:23 -07:00
Adrian Bunk 3e206b0a66 [PATCH] drivers/isdn/i4l/: possible cleanups
This patch contains the following possible cleanups:
- make needlessly global code static
- remove the following unused global function:
  - isdn_audio.c: isdn_audio_2adpcm_flush
- remove the following unused struct:
  - isdn_net.c: isdn_concap_demand_dial_dops

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 16:24:56 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00