1. 17 Oct, 2015 2 commits
    • Peter Hurley's avatar
      tty: r3964: Replace/remove bogus tty lock use · aba24888
      Peter Hurley authored
      The tty lock is strictly for serializing tty lifetime events
      (open/close/hangup), and not for line discipline serialization.
      
      The tty core already provides serialization of concurrent writes
      to the same tty, and line discipline lifetime management (by ldisc
      references), so pinning the tty via tty_lock() is unnecessary and
      counter-productive; remove tty lock use.
      
      However, the line discipline is responsible for serializing reads
      (if required by the line discipline); add read_lock mutex to
      serialize calls of r3964_read().
      Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      aba24888
    • Peter Hurley's avatar
      tty: r3964: Use tty->read_wait waitqueue · 9b9ab1b3
      Peter Hurley authored
      The tty core provides read_wait waitqueue specifically for line
      disciplines to wait readers; otherwise, the line discipline may
      miss wakeups generated by the tty core.
      
      NB: The tty core already provides serialization for the line discipline's
      close() method, and guarantees no readers or writers will be using the
      closing instance of the line discipline. Completely remove that wakeup.
      Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9b9ab1b3
  2. 08 Dec, 2013 1 commit
  3. 10 Aug, 2012 1 commit
    • Alan Cox's avatar
      tty: localise the lock · 89c8d91e
      Alan Cox authored
      The termios and other changes mean the other protections needed on the driver
      tty arrays should be adequate. Turn it all back on.
      
      This contains pieces folded in from the fixes made to the original patches
      
      | From: Geert Uytterhoeven <geert@linux-m68k.org>	(fix m68k)
      | From: Paul Gortmaker <paul.gortmaker@windriver.com>	(fix cris)
      | From: Jiri Kosina <jkosina@suze.cz>			(lockdep)
      | From: Eric Dumazet <eric.dumazet@gmail.com>		(lockdep)
      Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      89c8d91e
  4. 16 Jul, 2012 1 commit
  5. 06 Jul, 2012 1 commit
    • Alan Cox's avatar
      tty: localise the lock · f5e3bcc5
      Alan Cox authored
      The termios and other changes mean the other protections needed on the driver
      tty arrays should be adequate. Turn it all back on.
      
      This contains pieces folded in from the fixes made to the original patches
      
      | From: Geert Uytterhoeven <geert@linux-m68k.org>	(fix m68k)
      | From: Paul Gortmaker <paul.gortmaker@windriver.com>	(fix cris)
      | From: Jiri Kosina <jkosina@suze.cz>			(lockdep)
      | From: Eric Dumazet <eric.dumazet@gmail.com>		(lockdep)
      Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f5e3bcc5
  6. 02 Jun, 2012 1 commit
    • Linus Torvalds's avatar
      tty: Revert the tty locking series, it needs more work · f309532b
      Linus Torvalds authored
      This reverts the tty layer change to use per-tty locking, because it's
      not correct yet, and fixing it will require some more deep surgery.
      
      The main revert is d29f3ef3 ("tty_lock: Localise the lock"), but
      there are several smaller commits that built upon it, they also get
      reverted here. The list of reverted commits is:
      
        fde86d31 - tty: add lockdep annotations
        8f6576ad - tty: fix ldisc lock inversion trace
        d3ca8b64 - pty: Fix lock inversion
        b1d679af - tty: drop the pty lock during hangup
        abcefe5f - tty/amiserial: Add missing argument for tty_unlock()
        fd11b42e - cris: fix missing tty arg in wait_event_interruptible_tty call
        d29f3ef3 - tty_lock: Localise the lock
      
      The revert had a trivial conflict in the 68360serial.c staging driver
      that got removed in the meantime.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f309532b
  7. 04 May, 2012 1 commit
  8. 03 Jun, 2011 1 commit
    • Linus Torvalds's avatar
      Revert "tty: make receive_buf() return the amout of bytes received" · 55db4c64
      Linus Torvalds authored
      This reverts commit b1c43f82.
      
      It was broken in so many ways, and results in random odd pty issues.
      
      It re-introduced the buggy schedule_work() in flush_to_ldisc() that can
      cause endless work-loops (see commit a5660b41: "tty: fix endless
      work loop when the buffer fills up").
      
      It also used an "unsigned int" return value fo the ->receive_buf()
      function, but then made multiple functions return a negative error code,
      and didn't actually check for the error in the caller.
      
      And it didn't actually work at all.  BenH bisected down odd tty behavior
      to it:
        "It looks like the patch is causing some major malfunctions of the X
         server for me, possibly related to PTYs.  For example, cat'ing a
         large file in a gnome terminal hangs the kernel for -minutes- in a
         loop of what looks like flush_to_ldisc/workqueue code, (some ftrace
         data in the quoted bits further down).
      
         ...
      
         Some more data: It -looks- like what happens is that the
         flush_to_ldisc work queue entry constantly re-queues itself (because
         the PTY is full ?) and the workqueue thread will basically loop
         forver calling it without ever scheduling, thus starving the consumer
         process that could have emptied the PTY."
      
      which is pretty much exactly the problem we fixed in a5660b41.
      
      Milton Miller pointed out the 'unsigned int' issue.
      Reported-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Reported-by: default avatarMilton Miller <miltonm@bga.com>
      Cc: Stefan Bigler <stefan.bigler@keymile.com>
      Cc: Toby Gray <toby.gray@realvnc.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      55db4c64
  9. 22 Apr, 2011 1 commit
  10. 01 Mar, 2011 1 commit
  11. 05 Nov, 2010 1 commit
  12. 18 Oct, 2010 1 commit
  13. 10 Aug, 2010 2 commits
  14. 04 Dec, 2009 1 commit
  15. 12 Jul, 2009 1 commit
  16. 22 Jun, 2009 1 commit
  17. 02 Jan, 2009 1 commit
  18. 13 Oct, 2008 1 commit
  19. 20 Jul, 2008 1 commit
    • Alan Cox's avatar
      tty: Ldisc revamp · a352def2
      Alan Cox authored
      Move the line disciplines towards a conventional ->ops arrangement.  For
      the moment the actual 'tty_ldisc' struct in the tty is kept as part of
      the tty struct but this can then be changed if it turns out that when it
      all settles down we want to refcount ldiscs separately to the tty.
      
      Pull the ldisc code out of /proc and put it with our ldisc code.
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a352def2
  20. 30 Apr, 2008 2 commits
    • Alan Cox's avatar
      tty: The big operations rework · f34d7a5b
      Alan Cox authored
      - Operations are now a shared const function block as with most other Linux
        objects
      
      - Introduce wrappers for some optional functions to get consistent behaviour
      
      - Wrap put_char which used to be patched by the tty layer
      
      - Document which functions are needed/optional
      
      - Make put_char report success/fail
      
      - Cache the driver->ops pointer in the tty as tty->ops
      
      - Remove various surplus lock calls we no longer need
      
      - Remove proc_write method as noted by Alexey Dobriyan
      
      - Introduce some missing sanity checks where certain driver/ldisc
        combinations would oops as they didn't check needed methods were present
      
      [akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
      [akpm@linux-foundation.org: fix isicom]
      [akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
      [akpm@linux-foundation.org: fix kgdb]
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      Cc: Jason Wessel <jason.wessel@windriver.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f34d7a5b
    • Alan Cox's avatar
      tty: BKL pushdown · 04f378b1
      Alan Cox authored
      - Push the BKL down into the line disciplines
      - Switch the tty layer to unlocked_ioctl
      - Introduce a new ctrl_lock spin lock for the control bits
      - Eliminate much of the lock_kernel use in n_tty
      - Prepare to (but don't yet) call the drivers with the lock dropped
        on the paths that historically held the lock
      
      BKL now primarily protects open/close/ldisc change in the tty layer
      
      [jirislaby@gmail.com: a couple of fixes]
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      04f378b1
  21. 16 Jul, 2007 1 commit
  22. 08 May, 2007 1 commit
  23. 12 Feb, 2007 1 commit
    • Jiri Slaby's avatar
      [PATCH] Char: timers cleanup · 40565f19
      Jiri Slaby authored
      - Use timer macros to set function and data members and to modify
        expiration time.
      - Use DEFINE_TIMER for global timers and do not init them at run-time in
        these cases.
      - del_timer_sync is common in most cases -- we want to wait for timer
        function if it's still running.
      Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
      Cc: Dave Airlie <airlied@linux.ie>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Dominik Brodowski <linux@dominikbrodowski.net>
      Cc: Alessandro Zummo <a.zummo@towertech.it>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Cc: Kylene Jo Hall <kjhall@us.ibm.com>
      Cc: Wim Van Sebroeck <wim@iguana.be>
      Acked-by: Dmitry Torokhov <dtor@mail.ru>	(Input bits)
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      40565f19
  24. 11 Feb, 2007 1 commit
  25. 13 Dec, 2006 1 commit
  26. 08 Dec, 2006 1 commit
    • Alan Cox's avatar
      [PATCH] tty: switch to ktermios · 606d099c
      Alan Cox authored
      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: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarMartin Peschke <mp3@de.ibm.com>
      Acked-by: default avatarPeter Oberparleiter <oberpar@de.ibm.com>
      Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      606d099c
  27. 25 Jun, 2006 1 commit
  28. 10 Jan, 2006 1 commit
    • Alan Cox's avatar
      [PATCH] TTY layer buffering revamp · 33f0f88f
      Alan Cox authored
      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: default avatarAlan Cox <alan@redhat.com>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Signed-off-by: default avatarHirokazu Takata <takata@linux-m32r.org>
      Signed-off-by: default avatarSerge Hallyn <serue@us.ibm.com>
      Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
      Signed-off-by: default avatarJohn Hawkes <hawkes@sgi.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      33f0f88f
  29. 17 Oct, 2005 1 commit
  30. 29 Sep, 2005 1 commit
  31. 23 Jun, 2005 1 commit
  32. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      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!
      1da177e4