linux-toradex.git/drivers/tty/vt, branch v3.7.3 Linux kernel for Apalis and Colibri modules tty vt: Fix a regression in command line edition 2012-11-22T00:45:32+00:00 Jean-François Moine moinejf@free.fr 2012-11-20T16:35:41+00:00 b1a925f44a3a21c538144e30b08f966cad7adb63 The commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c ("Fix line garbage in virtual console on command line edition") made a regression with some machines: some characters were not erased after line edition. This patch adjusts the number of moved characters and the size of the region to be updated. Signed-off-by: Jean-François Moine <moinejf@free.fr> Tested-by: Krzysztof Mazur <krzysiek@podlesie.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c
("Fix line garbage in virtual console on command line edition")
made a regression with some machines: some characters were not erased
after line edition.

This patch adjusts the number of moved characters and the size of the
region to be updated.

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Tested-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb 2012-10-13T02:16:58+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-10-13T02:16:58+00:00 6c536a17fa049d0fb690c1a947b97dbfd304a916 Pull KGDB/KDB fixes and cleanups from Jason Wessel: "Cleanups - Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c - Add module event hooks for simplified debugging with gdb Fixes - Fix kdb to stop paging with 'q' on bta and dmesg - Fix for data that scrolls off the vga console due to line wrapping when using the kdb pager New - The debug core registers for kernel module events which allows a kernel aware gdb to automatically load symbols and break on entry to a kernel module - Allow kgdboc=kdb to setup kdb on the vga console" * tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb: tty/console: fix warnings in drivers/tty/serial/kgdboc.c kdb,vt_console: Fix missed data due to pager overruns kdb: Fix dmesg/bta scroll to quit with 'q' kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell kgdb,x86: fix warning about unused variable mips,kgdb: fix recursive page fault with CONFIG_KPROBES kgdb: Add module event hooks 
Pull KGDB/KDB fixes and cleanups from Jason Wessel:
 "Cleanups
   - Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
   - Add module event hooks for simplified debugging with gdb
 Fixes
   - Fix kdb to stop paging with 'q' on bta and dmesg
   - Fix for data that scrolls off the vga console due to line wrapping
     when using the kdb pager
 New
   - The debug core registers for kernel module events which allows a
     kernel aware gdb to automatically load symbols and break on entry
     to a kernel module
   - Allow kgdboc=kdb to setup kdb on the vga console"

* tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  tty/console: fix warnings in drivers/tty/serial/kgdboc.c
  kdb,vt_console: Fix missed data due to pager overruns
  kdb: Fix dmesg/bta scroll to quit with 'q'
  kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell
  kgdb,x86: fix warning about unused variable
  mips,kgdb: fix recursive page fault with CONFIG_KPROBES
  kgdb: Add module event hooks
kdb,vt_console: Fix missed data due to pager overruns 2012-10-12T11:37:35+00:00 Jason Wessel jason.wessel@windriver.com 2012-08-27T03:37:03+00:00 17b572e82032bc246324ce136696656b66d4e3f1 It is possible to miss data when using the kdb pager. The kdb pager does not pay attention to the maximum column constraint of the screen or serial terminal. This result is not incrementing the shown lines correctly and the pager will print more lines that fit on the screen. Obviously that is less than useful when using a VGA console where you cannot scroll back. The pager will now look at the kdb_buffer string to see how many characters are printed. It might not be perfect considering you can output ASCII that might move the cursor position, but it is a substantially better approximation for viewing dmesg and trace logs. This also means that the vt screen needs to set the kdb COLUMNS variable. Cc: <stable@vger.kernel.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> 
It is possible to miss data when using the kdb pager.  The kdb pager
does not pay attention to the maximum column constraint of the screen
or serial terminal.  This result is not incrementing the shown lines
correctly and the pager will print more lines that fit on the screen.
Obviously that is less than useful when using a VGA console where you
cannot scroll back.

The pager will now look at the kdb_buffer string to see how many
characters are printed.  It might not be perfect considering you can
output ASCII that might move the cursor position, but it is a
substantially better approximation for viewing dmesg and trace logs.

This also means that the vt screen needs to set the kdb COLUMNS
variable.

Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
tty vt: Fix line garbage in virtual console on command line edition 2012-09-10T23:35:46+00:00 Jean-François Moine moinejf@free.fr 2012-09-06T17:24:13+00:00 81732c3b2fede049a692e58a7ceabb6d18ffb18c On some machines using a specific hardware for console screen output, the update of the pixel frame buffer does not work correctly when using command line edition. This may be due to a memory cache bug in the machine on which the problem has been found, but an other solution is possible. This patch proposes to avoid touching directly the pixel frame buffer and to rebuild each character using the standard putc() function on command line edition. The resulting code is smaller and not obviously slower (no read access to the pixel frame buffer). Tested on a Cubox (ARM Marvell Dove 88AP510 SoC). Signed-off-by: Jean-François Moine <moinejf@free.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
On some machines using a specific hardware for console screen output,
the update of the pixel frame buffer does not work correctly when
using command line edition. This may be due to a memory cache bug
in the machine on which the problem has been found, but an other
solution is possible.

This patch proposes to avoid touching directly the pixel frame buffer
and to rebuild each character using the standard putc() function
on command line edition.

The resulting code is smaller and not obviously slower (no read
access to the pixel frame buffer).

Tested on a Cubox (ARM Marvell Dove 88AP510 SoC).

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: fix race in vt_waitactive() 2012-07-26T20:37:02+00:00 Rabin Vincent rabin.vincent@stericsson.com 2012-05-21T08:08:42+00:00 a7b12929be6cc55eab2dac3330fa9f5984e12dda pm_restore_console() is called from the suspend/resume path, and this calls vt_move_to_console(), which calls vt_waitactive(). There's a race in this path which causes the process which requests the suspend to sleep indefinitely waiting for an event which already happened: P1 P2 vt_move_to_console() set_console() schedule_console_callback() vt_waitactive() check n == fg_console +1 console_callback() switch_screen() vt_event_post() // no waiters vt_event_wait() // forever Fix the race by ensuring we're registered for the event before we check if it's already completed. Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
pm_restore_console() is called from the suspend/resume path, and this
calls vt_move_to_console(), which calls vt_waitactive().

There's a race in this path which causes the process which requests the
suspend to sleep indefinitely waiting for an event which already
happened:

P1                                      P2
 vt_move_to_console()
  set_console()
    schedule_console_callback()
  vt_waitactive()
    check n == fg_console +1
                                       console_callback()
                                         switch_screen()
                                         vt_event_post() // no waiters

    vt_event_wait() // forever

Fix the race by ensuring we're registered for the event before we check
if it's already completed.

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Move the handling of the tty release logic 2012-07-17T16:13:38+00:00 Alan Cox alan@linux.intel.com 2012-07-17T16:06:57+00:00 36b3c070d2346c890d690d71f6eab02f8c511137 Now that we don't have tty->termios tied to drivers->tty we can untangle the logic here. In addition we can push the removal logic out of the destructor path. At that point we can think about sorting out tty_port and console and all the other ugly hangovers. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Now that we don't have tty->termios tied to drivers->tty we can untangle
the logic here. In addition we can push the removal logic out of the
destructor path.

At that point we can think about sorting out tty_port and console and all
the other ugly hangovers.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: fix the keyboard/led locking 2012-07-17T16:13:37+00:00 Alan Cox alan@linux.intel.com 2012-07-17T16:06:41+00:00 3db1ddb725dcd9a2bb32be2b64d0688c3e1c4579 We touch the LED from both keyboard callback and direct paths. In one case we've got the lock held way up the call chain and in the other we haven't. This leads to complete insanity so fix it by giving the LED bits their own lock. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We touch the LED from both keyboard callback and direct paths. In
one case we've got the lock held way up the call chain and in the
other we haven't. This leads to complete insanity so fix it by giving
the LED bits their own lock.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: move the termios object into the tty 2012-07-16T20:00:41+00:00 Alan Cox alan@linux.intel.com 2012-07-14T14:31:47+00:00 adc8d746caa67fff4b53ba3e5163a6cbacc3b523 This will let us sort out a whole pile of tty related races. The alternative would be to keep points and refcount the termios objects. However 1. They are tiny anyway 2. Many devices don't use the stored copies 3. We can remove a pty special case Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: keyboard.c: Remove locking from vt_get_leds. 2012-07-06T21:28:17+00:00 Christopher Brannon chris@the-brannons.com 2012-06-22T13:16:34+00:00 157a4b311c45c9aba75a990464d9680867dc8805 There are three call sites for this function, and all three are called within a keyboard handler. kbd_event_lock is already held within keyboard handlers, so attempting to lock it in vt_get_leds causes deadlock. Signed-off-by: Christopher Brannon <chris@the-brannons.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
There are three call sites for this function, and all three
are called within a keyboard handler.
kbd_event_lock is already held within keyboard handlers,
so attempting to lock it in vt_get_leds causes deadlock.

Signed-off-by: Christopher Brannon <chris@the-brannons.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: fix race in vt_waitactive() 2012-06-15T00:10:08+00:00 Rabin Vincent rabin.vincent@stericsson.com 2012-05-21T08:08:42+00:00 2fc46915ecfbc51afcf995901f6ade7c3d503a25 pm_restore_console() is called from the suspend/resume path, and this calls vt_move_to_console(), which calls vt_waitactive(). There's a race in this path which causes the process which requests the suspend to sleep indefinitely waiting for an event which already happened: P1 P2 vt_move_to_console() set_console() schedule_console_callback() vt_waitactive() check n == fg_console +1 console_callback() switch_screen() vt_event_post() // no waiters vt_event_wait() // forever Fix the race by ensuring we're registered for the event before we check if it's already completed. Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
pm_restore_console() is called from the suspend/resume path, and this
calls vt_move_to_console(), which calls vt_waitactive().

There's a race in this path which causes the process which requests the
suspend to sleep indefinitely waiting for an event which already
happened:

P1                                      P2
 vt_move_to_console()
  set_console()
    schedule_console_callback()
  vt_waitactive()
    check n == fg_console +1
                                       console_callback()
                                         switch_screen()
                                         vt_event_post() // no waiters

    vt_event_wait() // forever

Fix the race by ensuring we're registered for the event before we check
if it's already completed.

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>