Recently my console UTF-8 patch went mainline.  Here is an additional patch
that fixes two nasty issues and improves a third one, namely:

1. My patch changed the behavior if a glyph is not found in the Unicode
   mapping table. Previously for Unicode values less than 256 or 512 the
   kernel tried to display the glyph from that position of the glyph table,
   which could lead to a different accented letter being displayed. I
   removed this fallback possibility and changed it to display the
   replacement symbol.

   As Behdad pointed out, some fonts (e.g. sun12x22 from the kbd package)
   lack Unicode mapping information, hence all you get is lots of question
   marks. Though theoretically it's actually a user-space bug (the font
   should be fixed), Behdad and I both believe that it'd be good to work
   around in the kernel by re-introducing the fallback solution for ASCII
   characters only. This sounds a quite reasonable decision, since all fonts
   ship the ASCII characters in the first 128 positions. This way users
   won't be surprised by lots of question marks just because s/he issued a
   not-so-perfectly parameterized setfont command. As this fallback is only
   re-introduced for code points below 128, you still won't see an accented
   letter replaced by another, but at least you'll always get the English
   letters right.

2. My patch introduced "question mark with inverted color attributes" as a
   last resort fallback glyph. Though it perfectly works on VGA console, on
   framebuffer you may end up with question marks that are highlighed but
   shouldn't be, and normal characters that are accidentally highlighed.
   This is caused by missing FLUSHes when changing the color attribute.

3. I've updated the table of double-width character based on Markus's
   updated version. Only ten new code poings (one interval) is added.
Signed-off-by: NEgmont Koblinger <egmont@uhulinux.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The virtual console driver uses a semaphore as mutex.  Use the mutex API
instead of the (binary) semaphore.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Create a variable, default_utf8, that defines the system-wide default UTF-8
setting.  This variable can be altered via sysfs. If the variable is properly
set, this should mimimize breakage of UTF-8 encoded consoles when doing a
reset or echo -e '\033c' and of newly opened/allocated consoles.

This is based from patches by Jan Engelhardt and Paul LeoNerd Evans.
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Paul LeoNerd Evans <leonerd@leonerd.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add color support to the "underline" and "italic" attributes as in
OpenBSD/NetBSD-style (vt220) and xterm.
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Acked-by: N"Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allow for the palette to be exposed and changed via sysfs.  A call to
/usr/bin/reset will slurp the new definitions in for the current console.

Already posted at http://lkml.org/lkml/2006/1/15/149Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The UTF-8 part of the vt driver suffers from the following issues which are
addressed in my patch:

1) If there's no glyph found for a particular valid UTF-8 character, we try
   to display U+FFFD. However if this one is not found either, here's what
   the current kernel does:

   - First, if the Unicode value is less than the number of glyphs, use the
     glyph directly from that position of the glyph table. While it may be a
     good idea in the 8-bit world, it has absolutely no sense with Unicode
     in mind. For example, if a Latin-2 font is loaded and an application
     prints U+00FB ("u with circumflex", not present in Latin-2) then as a
     fallback solution the glyph from the 0xFB position of the Latin-2
     fontset (which is an "u with double accent" - a different character) is
     displayed.

   - Second, if this fallback fails too, a simple ASCII question mark is
     printed, which is visually undistinguishable from a real question mark.

   I changed the code to skip the first step (except if in non-UTF-8 mode),
   and changed the second step to print the question mark with inverse color
   attributes, so it is visually clear that it's not a real question mark,
   and resembles more to the common glyph of U+FFFD.

2) The UTF-8 decoder is buggy in many ways:

   - Lone continuation bytes (section 3.1 of Markus Kuhn's UTF-8 stress
     test) are not caught, they are displayed as some "random" (taken
     directly form the font table, see above) glyphs instead the replacement
     character.

   - Incomplete sequences (sections 3.2 and 3.3 of the stress test) emit no
     replacement character, but rather cause the subsequent valid character
     to be displayed more times(!).

   - The decoder is not safe: overlong sequences are not caught currently,
     they are displayed as if these were valid representations. This may
     even have security impacts.

   - The decoder does not handle D800..DFFF and FFFE..FFFF specially, it
     just emits these code points and lets it be looked up in the glyph
     table. Since these are invalid code points, I replace them by U+FFFD
     and hence give no chance for them to be looked up in the glyph table.
     (Assuming no font ships glyphs for these code points, this change is
     not visible to the users since the glyph shown will be the same.)

   With my fixes to the decoder it now behaves exactly as Markus Kuhn's
   stress test recommends.

3) It has no concept of double-width (CJK) characters. It's way beyond the
   scope of my patch to try to display them, but at least I think it's
   important for the cursor to jump two positions when printing such
   characters, since this is what applications (such as text editors)
   expect. Currently the cursor only jumps one position, and hence
   applications suffer from displaying and refreshing problems, and editing
   some English letters that are preceded by some CJK characters in the same
   line is a nightmare. With my patch an additional space is inserted after
   the CJK character has been printed (which usually means a replacement
   symbol of course). (If U+FFFD isn't availble and hence an inverse
   question mark is displayed in the first cell, I keep the inverted state
   for the space in the 2nd column so it's quite easy to see that they are
   tied together.)

4) There is a small built-in table of zero-width spaces that are not to be
   printed but silently skipped. U+200A is included there, but it's not a
   zero-width character, so I remove it from there.
Signed-off-by: NEgmont Koblinger <egmont@uhulinux.hu>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Initialise the SAK member of the vc_cons variable on all virtual terminals,
not only the first one.  This prevents an oops when trying Sysrq-C on e.g.
the second virtual terminal:

  kernel BUG at kernel/workqueue.c:212!
  invalid opcode: 0000 [1] SMP
  CPU 0
  Modules linked in: i915 drm deflate zlib_deflate twofish twofish_common serpent blowfish des ce
  Pid: 0, comm: swapper Not tainted 2.6.21-rc3-default #15
  RIP: 0010:[<ffffffff8028c955>]  [<ffffffff8028c955>] queue_work+0x32/0x51
  RSP: 0018:ffffffff805fada8  EFLAGS: 00010013
  RAX: ffffffff80683f38 RBX: ffffffff804ae700 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffffffff80683f30 RDI: ffff81000134a840
  RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000002
  R10: ffffffff805990e0 R11: ffff810037f4c0f0 R12: 000000000000006b
  R13: ffff81007aa23000 R14: 0000000000000001 R15: 0000000000000096
  FS:  0000000000000000(0000) GS:ffffffff804d8000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
  CR2: 00002b72026e9000 CR3: 0000000079175000 CR4: 00000000000006e0
  Process swapper (pid: 0, threadinfo ffffffff8059e000, task ffffffff80490840)
  Stack:  0000000000000096 ffffffff803635db ffffffff805fadf8 0000000000000001
   ffff8100013c2e40 0000000000000025 ffff81007c931c00 ffff81007aa23000
   0000000000000001 ffffffff8035e3ee 0000000000000092 ffff810037cc8000
  Call Trace:
   <IRQ>  [<ffffffff803635db>] __handle_sysrq+0x98/0x129
   [<ffffffff8035e3ee>] kbd_event+0x32e/0x56a
   [<ffffffff8037d502>] input_event+0x422/0x44a
   [<ffffffff80381d71>] atkbd_interrupt+0x449/0x503
   [<ffffffff8037a42d>] serio_interrupt+0x37/0x6f
   [<ffffffff8037affb>] i8042_interrupt+0x1f4/0x20a
   [<ffffffff8026bd20>] smp_send_timer_broadcast_ipi+0x2d/0x4e
   [<ffffffff8020eee5>] handle_IRQ_event+0x25/0x53
   [<ffffffff802a924c>] handle_edge_irq+0xe4/0x128
   [<ffffffff802562ac>] call_softirq+0x1c/0x28
   [<ffffffff802632eb>] do_IRQ+0x6c/0xd3
   [<ffffffff8024f4e7>] mwait_idle+0x0/0x45
   [<ffffffff80255631>] ret_from_intr+0x0/0xa
   <EOI>  [<ffffffff80248a4d>] datagram_poll+0x0/0xc8
   [<ffffffff8024f529>] mwait_idle+0x42/0x45
   [<ffffffff80242c05>] cpu_idle+0x8b/0xae
   [<ffffffff805a8779>] start_kernel+0x2b9/0x2c5
   [<ffffffff805a815e>] _sinittext+0x15e/0x162

  Code: 0f 0b eb fe 48 8b 07 48 63 d2 48 f7 d0 48 8b 3c d0 e8 13 ff
  RIP  [<ffffffff8028c955>] queue_work+0x32/0x51
   RSP <ffffffff805fada8>
  Kernel panic - not syncing: Aiee, killing interrupt handler!
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Acked-by: NEric Biederman <ebiederm@xmission.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When the console is in VT_AUTO+KD_GRAPHICS mode, switching to the
SUSPEND_CONSOLE fails, resulting in vt_waitactive() waiting indefinitely or
until the task is interrupted.  This patch tests if a console switch can
occur in set_console() and returns early if a console switch is not
possible.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: NAndrew Johnson <ajohnson@intrinsyc.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Somewhere in the rewrite of the work queues my cleanup of SAK handling
got broken.  Maybe I didn't retest it properly or possibly the API
was changing so fast I missed something.  Regardless currently
triggering a SAK now generates an ugly BUG_ON and kills the kernel.

Thanks to Alexey Dobriyan <adobriyan@openvz.org> for spotting this.

This modifies the use of SAK_work to initialize it when the data
structure it resides in is initialized, and to simply call
schedule_work when we need to generate a SAK.  I update both
data structures that have a SAK_work member for consistency.

All of the old PREPARE_WORK calls that are now gone.

If we call schedule_work again before it has processed it
has generated the first SAK it will simply ignore the duplicate
schedule_work request.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Of kernel subsystems that work with pids the tty layer is probably the largest
consumer.  But it has the nice virtue that the assiation with a session only
lasts until the session leader exits.  Which means that no reference counting
is required.  So using struct pid winds up being a simple optimization to
avoid hash table lookups.

In the long term the use of pid_nr also ensures that when we have multiple pid
spaces mixed everything will work correctly.
Signed-off-by: NEric W. Biederman <eric@maxwell.lnxi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- 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: NJiri 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add proper prototypes for two functions in drivers/char/vc_screen.c
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Run this:

	#!/bin/sh
	for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do
	  echo "De-casting $f..."
	  perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f
	done

And then go through and reinstate those cases where code is casting pointers
to non-pointers.

And then drop a few hunks which conflicted with outstanding work.

Cc: Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Greg KH <greg@kroah.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Karsten Keil <kkeil@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Steven French <sfrench@us.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

[akpm@osdl.org: bugfix]
Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Converts from using struct "class_device" to "struct device" making
everything show up properly in /sys/devices/ with symlinks from the
/sys/class directory.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

This patch adds proper prototypes to header files for three console init
functions used on drivers/char/vt.c
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Check the return value of device_create_file().  If return is 'fail', remove
attributes by calling device_remove_file().
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NJeff Dike <jdike@addtoit.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I took a good hard look at the locking and it appears the locking on vt_pid
is the console semaphore.  Every modified path is called under the console
semaphore except reset_vc when it is called from fn_SAK or do_SAK both of
which appear to be in interrupt context.  In addition I need to be careful
because in the presence of an oops the console_sem may be arbitrarily
dropped.

Which leads me to conclude the current locking is inadequate for my needs.

Given the weird cases we could hit because of oops printing instead of
introducing an extra spin lock to protect the data and keep the pid to
signal and the signal to send in sync, I have opted to use xchg on just the
struct pid * pointer instead.

Due to console_sem we will stay in sync between vt_pid and vt_mode except
for a small window during a SAK, or oops handling.  SAK handling should
kill any user space process that care, and oops handling we are broken
anyway.  Besides the worst that can happen is that I try to send the wrong
signal.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Memory leaks can happen in the vc_resize() function in drivers/char/vt.c
because of the vc->vc_screenbuf variable overriding in vc_allocate().  The
kmemleak reported trace is as follows:

  <__kmalloc>
  <vc_resize>
  <fbcon_init>
  <visual_init>
  <vc_allocate>
  <con_open>
  <tty_open>
  <chrdev_open>

This patch no longer allocates a screen buffer in vc_allocate() if it was
already allocated by vc_resize().
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: N"Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current kernel serializes console resizes but does not serialize the
resize against the tty structure updates.  This means that while two
parallel resizes cannot mess up the console you can get incorrect results
reported.

Secondly while doing this I added vc_lock_resize() to lock and resize the
console.  This leaves all knowledge of the console_sem in the vt/console
driver and kicks it out of the tty layer, which is good

Thirdly while doing this I decided I couldn't stand "disallocate" any
longer so I switched it to "deallocate".
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix utf-8 mode so alternate charset modes always work according to control
sequences interpreted in do_con_trol function preserving backward US-ASCII
and VT100 semigraphics compatibility.

Malformed utf-8 sequences are represented as sequences of replacement
glyphs,original codes or '?' as a last resort.

unicode-xterm, gnome-terminal, kconsole and other terminal emulators in
utf-8 mode respect acsc, enacs, rmacs sequences.  Also I found that some
important system programs (from Debian distro) uses acsc in utf-8 mode -
dselect, aptitude, w3m for example.
Signed-off-by: NAdam Tlalka <atlka@pg.gda.pl>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Jon Smirl noted a couple of tty driver functions now are quite misleadingly
named with the death of devfs.  A quick grep found another case in the lp
driver.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When a VT is newly allocated, the module reference count of the backend
will be incremented.  This should be balanced by a module_put() when this
VT is deallocated.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Also fixes all drivers that set this field.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Also fixes up all files that #include it.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

To enable this feature, CONFIG_VT_HW_CONSOLE_BINDING must be set to 'y'.  This
feature will default to 'n' to minimize users accidentally corrupting their
virtual terminals.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add sysfs control to the VT layer.  A new sysfs class, 'vtconsole', and class
devices 'vtcon[n]' are added.  Each class device file has the following
attributes:

/sys/class/vtconsole/vtcon[n]/name - read-only attribute showing the
                                     name of the current backend

/sys/class/vtconsole/vtcon[n]/bind - read/write attribute
             where: 0 - backend is unbound/unbind backend from the VT layer
                    1 - backend is bound/bind backend to the VT layer

In addition, if any of the consoles are in KD_GRAPHICS mode, binding and
unbinding will not succeed.  KD_GRAPHICS mode usually indicates that the
underlying console hardware is used for other purposes other than displaying
text (ie X).  This feature should prevent binding/unbinding from interfering
with a graphics application using the VT.

[akpm@osdl.org: warning fixes]
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The framebuffer console is now able to dynamically bind and unbind from the VT
console layer.  Due to the way the VT console layer works, the drivers
themselves decide when to bind or unbind.  However, it was decided that
binding must be controlled, not by the drivers themselves, but by the VT
console layer.  With this, dynamic binding is possible for all VT console
drivers, not just fbcon.

Thus, the VT console layer will impose the following to all VT console
drivers:

- all registered VT console drivers will be entered in a private list
- drivers can register themselves to the VT console layer, but they cannot
  decide when to bind or unbind. (Exception: To maintain backwards
  compatibility, take_over_console() will automatically bind the driver after
  registration.)
- drivers can remove themselves from the list by unregistering from the VT
  console layer. A prerequisite for unregistration is that the driver must not
  be bound.

The following functions are new in the vt.c:

register_con_driver() - public function, this function adds the VT console
driver to an internal list maintained by the VT console

bind_con_driver() - private function, it binds the driver to the console

take_over_console() is changed to call register_con_driver() followed by a
bind_con_driver().  This is the only time drivers can decide when to bind to
the VT layer.  This is to maintain backwards compatibility.

unbind_con_driver() - private function, it unbinds the driver from its
console.  The vacated consoles will be taken over by the default boot console
driver.

unregister_con_driver() - public function, removes the driver from the
internal list maintained by the VT console.  It will only succeed if the
driver is currently unbound.

con_is_bound() checks if the driver is currently bound or not

give_up_console() is just a wrapper to unregister_con_driver().

There are also 3 additional functions meant to be called only by the tty layer
for sysfs control:

	vt_bind() - calls bind_con_driver()
	vt_unbind() - calls unbind_con_driver()
	vt_show_drivers() - shows the list of registered drivers

Most VT console drivers will continue to work as is, but might have problems
when unbinding or binding which should be fixable with minimal changes.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To allow for detaching fbcon, it must be able to give up the console.
However, the function give_up_console() is plain broken.  It just sets the
entries in the console driver map to NULL, it leaves the vt layer without a
console driver, and does not decrement the module reference count.  Calling
give_up_console() is guaranteed to hang the machine..

To fix this problem, ensure that the virtual consoles are not left dangling
without a driver.  All systems have a default boot driver (either vgacon or
dummycon) which is never unloaded.  For those vt's that lost their driver, the
default boot driver is reassigned back to them.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Delay the update of the visible framebuffer console until all other consoles
have been initialized in order to avoid losing information.  This only seems
to be a problem with modules, not with built-in drivers.
Signed-off-by: NDavid Hollister <david.hollister@amd.com>
Signed-off-by: NJordan Crouse <jordan.crouse@amd.com>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

From: Andrew Morton <akpm@osdl.org>

Revert commit ff4da2e2.

It broke APM suspend, probably because APM doesn't switch back to a VT
when suspending.

Tracked down by Matt Mackall <mpm@selenic.com>

Rafael sayeth:
  "It only fixed the theoretical issue that a quick-handed user could
   switch to X after processes have been frozen and before the devices
   are suspended.

   With the current userland suspend tools it shouldn't be necessary."

Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add TIOCL_GETKMSGREDIRECT needed by the userland suspend tool to get the
current value of kmsg_redirect from the kernel so that it can save it and
restore it after resume.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@suse.cz>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It is unsafe to suspend devices if the hardware is controlled by X.  Add an
extra check to prevent this from happening.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When moving the cursor by writing to /dev/vcs*, the old cursor image is not
erased.  Fix by hiding the cursor first before moving the cursor to the new
position.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Current console blanking code is broken.  It will first do a normal blank,
then start the VESA blank timer if vesa_off_interval != 0, and then proceed
to do the VESA blanking directly.  After the timer expires it will do the
VESA blanking a second time.  Also the vesa_powerdown() function doesn't
allow all VESA modes to be used.

With this patch the behaviour is:
1. Blank: vesa_off_interval != 0 -> Do normal blank
          vesa_off_interval == 0 -> Do VESA blank
2. Start the VESA blank timer if vesa_off_interval != 0 and
   vesa_power_mode != 0.

It also gets rid of the limiting vesa_powerdown() function.
Signed-off-by: NVille Syrjala <syrjala@sci.fi>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the unlikely case of the new screen width much wider then the old,
use (old_row_size * new_rows) instead of new_screen_size to prevent a
buffer overrun during the copy.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>