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Commit Graph

184 Commits

Author SHA1 Message Date
Felipe Balbi
b1c43f82c5 tty: make receive_buf() return the amout of bytes received
it makes it simpler to keep track of the amount of
bytes received and simplifies how flush_to_ldisc counts
the remaining bytes. It also fixes a bug of lost bytes
on n_tty when flushing too many bytes via the USB
serial gadget driver.

Tested-by: Stefan Bigler <stefan.bigler@keymile.com>
Tested-by: Toby Gray <toby.gray@realvnc.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:31:53 -07:00
Govindraj.R
e9a470f445 Serial: Remove unused code.
Remove stale code in serial_core layer.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:33:37 -07:00
Petr Písař
f8df13e0a9 tty: Clean console safely
Traditional \E[2J sequence erases console display but scroll-back
buffer and underlying device (frame) buffer keep data that can be
accessed by scrolling console back.

This patch introduce new \E[J parameter 3 that allows to scramble
scroll-back buffer explicitly. Session locking programs (screen,
vlock) can use it to prevent attacker to browse locked console
history.

Signed-off-by: Petr Písař <ppisar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:33:37 -07:00
Jesper Juhl
d942060288 Serial: ifx6x60c: Remove duplicate includes of linux/tty.h
Including linux/tty.h 3 times is a little over the top - once will do.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:33:37 -07:00
Jovi Zhang
99edb3d10a tty: remove invalid location line in file header
remove invalid location line in each file header after location
moved from driver/char to driver/tty

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:33:36 -07:00
Jiri Slaby
6f5c24ad0f serial: core, remove uart_update_termios
Now, uart_update_termios is empty, so it's time to remove it. We no
longer need a live tty in .dtr_rts. So this should prune all the bugs
where tty is zeroed in port->tty during tty_port_block_til_ready.

There is one thing to note. We don't set ASYNC_NORMAL_ACTIVE now. It's
because this is done already in tty_port_block_til_ready.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:32:20 -07:00
Jiri Slaby
303a7a1199 serial: core, do not set DTR/RTS twice on startup
In .dtr_rts we do:
  uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS)
and call uart_update_termios. It does:
  uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS)
once again. As the only callsite of uart_update_termios is .dtr_rts,
remove the uart_set_mctrl from uart_update_termios to not set it twice.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:32:20 -07:00
Jiri Slaby
c7d7abff40 serial: core, move termios handling to uart_startup
We should not fiddle with speed and cflags in .dtr_rts hook. Actually
we might not have tty at that moment already.

So move the console cflag copy and speed setup into uart_startup.
Actually the speed setup is already there, but we need to call it
unconditionally (uart_startup is called from uart_open with hw_init =
0).

This means we move uart_change_speed before dtr/rts setup in .dtr_rts.
But this should not matter as the setup should be called after
uart_change_speed anyway.
Before:                             After:
dtr/rts setup (dtr_rts)             uart_change_speed (startup)
uart_change_speed (update_termios)  dtr/rts setup (dtr_rts)
dtr/rts setup (update_termios)      dtr/rts setup (update_termios)

The second setup will dismiss with the next patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:32:20 -07:00
Jiri Slaby
7c31bdb6b2 Char: moxa, do not touch NORMAL_ACTIVE bit
The bit is set in tty_port_block_til_ready (via moxa_open) and unset
in tty_port_close (via moxa_close). No need to pin it in the driver.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:32:19 -07:00
Tobias Klauser
a664ec9675 serial: altera_uart: Scan for a free port if platform device id is -1
Devices extracted from device tree all seem to have pdev->id set to -1.
Up until now we mapped all devices with id -1 to the first device.  This
behaviour could lead to problems when using more than one Altera UART in
a system.

This patch changes the behaviour of the driver to scan for the next free
id in case the id is -1.

Because we cannot refer back to the assigned id in altera_uart_remove,
the port instance needs to be stored in device drvdata.

Reported-by: David Smoot <davidsmoot@gmail.com>
Cc: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:31:19 -07:00
Jiri Slaby
0259894c73 TTY: fix fail path in tty_open
When tty_add_file fails we omit to clean up. Fix that by calling
tty_release appropriatelly.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:43:01 -07:00
Jiri Slaby
a9dccddb60 TTY: plug in deinitialize_tty_struct
Used the newly introduced deinitialize_tty_struct to properly shut
down ldisc.

It is intended to fix the Julian's reported problem. He reports that
kmemleak checker warns about memory leak:
unreferenced object 0xc0e19860 (size 8):
comm cat, pid 1226, jiffies 4294919464 (age 287.476s)
hex dump (first 8 bytes):
44 de 2d c1 01 00 00 00 D.-.....
backtrace:
[<c1065a74>] create_object+0x109/0x1ad
[<c1063d2b>] kmem_cache_alloc+0x60/0x68
[<c113505c>] tty_ldisc_get+0x54/0x76
[<c11358c9>] tty_ldisc_init+0xa/0x20
[<c1130ab4>] initialize_tty_struct+0x2d/0x1ac
[<c1130c8c>] tty_init_dev+0x59/0x10d
[<c113136d>] tty_open+0x24a/0x3a2
...

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:43:01 -07:00
Jiri Slaby
6716671d8c TTY: introduce deinit helpers for proper ldisc shutdown
Introduce deinitialize_tty_struct which should be called after
initialize_tty_struct and before successfull tty_ldisc_setup.

It calls tty_ldisc_deinit which is opposite of tty_ldisc_init. It only
puts a reference to ldisc and assigns NULL to tty->ldisc.

It will be used to shut down ldisc when tty_release cannot be called
yet.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:43:01 -07:00
Jiri Slaby
c18d77aa00 TTY: unify pty_unix98_install fail path handling
Change it so that we call the deinit functions at one place at the end
of the function (by gotos). And while at it use some sane label names.

This is a preparation for the deinitialization of tty in the next
patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:43:00 -07:00
Jiri Slaby
8a1b8d70a0 TTY: unify pty_install fail path handling
Change it so that we call the deinit functions at one place at the end
of the function (by gotos). And while at it use some sane label names.

This is a preparation for the deinitialization of tty in the next
patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:43:00 -07:00
Jiri Slaby
d554350375 TTY: unify tty_init_dev fail path handling
Change it so that we call the deinit functions at one place at the end
of the function (by gotos). And while at it use some sane label names.

This is a preparation for the deinitialization of tty in the next
patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:42:59 -07:00
Jiri Slaby
d65c57f4ec TTY: rocket, remove unused variables
drivers/tty/rocket.c:1393:2: warning: Value stored to 'cp' is never read
        cp = &info->channel;
        ^    ~~~~~~~~~~~~~~
drivers/tty/rocket.c:1412:2: warning: Value stored to 'cp' is never read
        cp = &info->channel;
        ^    ~~~~~~~~~~~~~~
drivers/tty/rocket.c:1730:2: warning: Value stored to 'cp' is never read
        cp = &info->channel;
        ^    ~~~~~~~~~~~~~~
drivers/tty/rocket.c:1825:3: warning: Value stored to 'str' is never read
                str = "8";
                ^     ~~~
[many 'str' warnings stripped]
drivers/tty/rocket.c:2037:3: warning: Value stored to 'board_type' is never read
                board_type = "RocketModem";
                ^            ~~~~~~~~~~~~~
[some 'board_type' warnings stripped]

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:41:48 -07:00
Jiri Slaby
9d86f71b59 Char: moxa, remove unused variables
drivers/tty/moxa.c:1287:2: warning: Value stored to 'port' is never read
        port = tty->index;
        ^      ~~~~~~~~~~
drivers/tty/moxa.c:1763:2: warning: Value stored to 'cflag' is never read
        cflag = termio->c_cflag;        /* termio->c_cflag */
        ^       ~~~~~~~~~~~~~~~

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:41:48 -07:00
Jiri Slaby
f2ee4ae87d TTY: VT, remove unused variables
drivers/tty/vt/vt.c:892:2: warning: Value stored to 'old_screen_size' is never read
        old_screen_size = vc->vc_screenbuf_size;
        ^                 ~~~~~~~~~~~~~~~~~~~~~
drivers/tty/vt/vt.c:890:2: warning: Value stored to 'old_cols' is never read
	old_cols = vc->vc_cols;
	^          ~~~~~~~~~~~

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:41:48 -07:00
Jiri Slaby
0e7f4194a0 Char: cyclades, fix unused variable
drivers/tty/cyclades.c:1454:2: warning: Value stored to 'channel' is never read
	channel = info->line - card->first_line;
	^         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix it by moving it to the appropriate debug section where it is used.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:41:47 -07:00
Jiri Slaby
4fd53ef5c9 TTY: serial_core, remove unused variable
drivers/tty/serial/serial_core.c:1980:2: warning: Value stored to 'tty' is never read
        tty = port->tty;
        ^     ~~~~~~~~~

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:41:47 -07:00
Jiri Slaby
52ea383aba tty: VT, remove unused variable
drivers/tty/vt/vt_ioctl.c:1525:2: warning: Value stored to 'kbd' is never read
kbd = kbd_table + console;
^     ~~~~~~~~~~~~~~~~~~~

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:41:46 -07:00
Andrew Morton
6da9e95f73 drivers/tty/vt/vt_ioctl.c: repair insane ?: expression
Cc: Arthur Taylor <art@ified.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:39:28 -07:00
Arthur Taylor
60680f97d7 vt: Add K_OFF return value to vt_ioctl KDGKBMODE
After adding support for K_OFF in KDSKBMODE, it was forgotten to
add support for returning it in KDGKBMODE.

Signed-off-by: Arthur Taylor <art@ified.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:39:28 -07:00
Herton Ronaldo Krzesinski
909bc7741b vt: remove uneeded retval check before tty->ops->open inside tty_open
The current check is uneeded, since !retval will always returns true,
as retval returned from tty_add_file is checked earlier and tty_open
exits if it's not zero.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 14:39:28 -07:00
Linus Torvalds
26cf445721 Merge branch 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: select ARCH_NO_SYSDEV_OPS.
  sh: fix build error in board-sh7757lcr.c
  sh: landisk: Remove whitespace
  sh: landisk: Remove mv_nr_irqs
  sh: sh-sci: Fix double initialization by serial_console_setup
  serial: sh-sci: prevent setup of uninitialized serial console
  dma: shdma: add checking the DMAOR_AE in sh_dmae_err
2011-04-07 12:48:45 -07:00
Linus Torvalds
42933bac11 Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6
* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6:
  Fix common misspellings
2011-04-07 11:14:49 -07:00
Linus Torvalds
a5660b41af tty: fix endless work loop when the buffer fills up
Commit f23eb2b2b2 ('tty: stop using "delayed_work" in the tty layer')
ended up causing hung machines on UP with no preemption, because the
work routine to flip the buffer data to the ldisc would endlessly re-arm
itself if the destination buffer had filled up.

With the delayed work, that only caused a timer-driving polling of the
tty state every timer tick, but without the delay we just ended up with
basically a busy loop instead.

Stop the insane polling, and instead make the code that opens up the
receive room re-schedule the buffer flip work.  That's what we should
have been doing anyway.

This same "poll for tty room" issue is almost certainly also the cause
of excessive kworker activity when idle reported by Dave Jones, who also
reported "flush_to_ldisc executing 2500 times a second" back in Nov 2010:

  http://lkml.org/lkml/2010/11/30/592

which is that silly flushing done every timer tick.  Wasting both power
and CPU for no good reason.

Reported-and-tested-by: Alexander Beregalov <a.beregalov@gmail.com>
Reported-and-tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-04 14:26:54 -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
Paul Mundt
7ea5db8efe Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into sh-latest 2011-03-31 15:39:47 +09:00
Nobuhiro Iwamatsu
6a8c979935 sh: sh-sci: Fix double initialization by serial_console_setup
The driver is initialized in a state with an unknown value by
serial_console_setup. And initialization fails.

This is caused by the initialization by sci_console_init.
This function does not seem to be necessary for the present sh-sci driver.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-03-31 14:33:24 +09:00
Alexandre Courbot
b2267a6b09 serial: sh-sci: prevent setup of uninitialized serial console
Commit 906b17dc08 introduced a condition
where the kernel will crash unless a earlyprintk parameter is specified.

Without this parameter, sci_console_init is called during early console
setup without any port being initialized, and the kernel crashes a
little bit later when uart_set_options attemps to invoke set_termios on a
port with an ops member equal to NULL.

This patch just checks in sci_console_init that the port is properly
initialized, and aborts the early console setup if it is not.

Signed-off-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-03-31 14:33:22 +09:00
David S. Miller
6cd7a63756 apbuart: Depend upon sparc.
It absolutely needs to be able to get at pdev_archdata members
which are sparc specific.

Signed-off-by: David S. Miller <davem@davemloft.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
2011-03-30 21:12:24 -07:00
Daniel Hellstrom
c897dcf631 sparc32,leon: Fixed APBUART frequency detection
The UARTs may be located on different APB buses, thus have

different UART clock frequency. The system frequency is not
the same (but often) as the UART frequency, rather the APB bus
frequency that the APBUART is located at has the same
frequency, so this looks at the "freq" property instead.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-30 04:28:54 -07:00
Daniel Hellstrom
10544f128c sparc32, leon: APBUART driver must use archdata to get IRQ number
See Commit id 1636f8ac2b (sparc/of:
Move of_device fields into struct pdev_archdata), this patch
is similar to 19e4875fb2 (of/sparc:
fix build regression from of_device changes)

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-30 04:28:54 -07:00
Thomas Gleixner
dced35aeb0 drivers: Final irq namespace conversion
Scripted with coccinelle.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-29 14:48:19 +02:00
Linus Torvalds
95e14ed7fc Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kdb: add usage string of 'per_cpu' command
  kgdb,x86_64: fix compile warning found with sparse
  kdb: code cleanup to use macro instead of value
  kgdboc,kgdbts: strlen() doesn't count the terminator
2011-03-25 21:04:56 -07:00
Dan Carpenter
adb4b83c12 kgdboc,kgdbts: strlen() doesn't count the terminator
This is an off by one because strlen() doesn't count the null
terminator.  We strcpy() these strings into an array of size
MAX_CONFIG_LEN.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-03-25 16:37:30 -05:00
David Rientjes
b2b755b5f1 lib, arch: add filter argument to show_mem and fix private implementations
Commit ddd588b5dd ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():

	lib/lib.a(show_mem.o): In function `show_mem':
	show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
	arch/sparc/mm/built-in.o:(.text+0xd70): first defined here

The fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.

Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24 17:49:37 -07:00
Julia Lawall
d9d691f584 drivers/tty/bfin_jtag_comm.c: avoid calling put_tty_driver on NULL
put_tty_driver calls tty_driver_kref_put on its argument, and then
tty_driver_kref_put calls kref_put on the address of a field of this
argument.  kref_put checks for NULL, but in this case the field is likely
to have some offset and so the result of taking its address will not be
NULL.  Labels are added to be able to skip over the call to put_tty_driver
when the argument will be NULL.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression *x;
@@

*if (x == NULL)
{ ...
* put_tty_driver(x);
  ...
  return ...;
}
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Torben Hohn <torbenh@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:46:39 -07:00
Linus Torvalds
f23eb2b2b2 tty: stop using "delayed_work" in the tty layer
Using delayed-work for tty flip buffers ends up causing us to wait for
the next tick to complete some actions.  That's usually not all that
noticeable, but for certain latency-critical workloads it ends up being
totally unacceptable.

As an extreme case of this, passing a token back-and-forth over a pty
will take two ticks per iteration, so even just a thousand iterations
will take 8 seconds assuming a common 250Hz configuration.

Avoiding the whole delayed work issue brings that ping-pong test-case
down to 0.009s on my machine.

In more practical terms, this latency has been a performance problem for
things like dive computer simulators (simulating the serial interface
using the ptys) and for other environments (Alan mentions a CP/M emulator).

Reported-by: Jef Driesen <jefdriesen@telenet.be>
Acked-by: Greg KH <gregkh@suse.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 16:17:32 -07:00
Linus Torvalds
e16b396ce3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits)
  doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore
  Update cpuset info & webiste for cgroups
  dcdbas: force SMI to happen when expected
  arch/arm/Kconfig: remove one to many l's in the word.
  asm-generic/user.h: Fix spelling in comment
  drm: fix printk typo 'sracth'
  Remove one to many n's in a word
  Documentation/filesystems/romfs.txt: fixing link to genromfs
  drivers:scsi Change printk typo initate -> initiate
  serial, pch uart: Remove duplicate inclusion of linux/pci.h header
  fs/eventpoll.c: fix spelling
  mm: Fix out-of-date comments which refers non-existent functions
  drm: Fix printk typo 'failled'
  coh901318.c: Change initate to initiate.
  mbox-db5500.c Change initate to initiate.
  edac: correct i82975x error-info reported
  edac: correct i82975x mci initialisation
  edac: correct commented info
  fs: update comments to point correct document
  target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c
  ...

Trivial conflict in fs/eventpoll.c (spelling vs addition)
2011-03-18 10:37:40 -07:00
Linus Torvalds
0a95d92c00 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (62 commits)
  powerpc/85xx: Fix signedness bug in cache-sram
  powerpc/fsl: 85xx: document cache sram bindings
  powerpc/fsl: define binding for fsl mpic interrupt controllers
  powerpc/fsl_msi: Handle msi-available-ranges better
  drivers/serial/ucc_uart.c: Add of_node_put to avoid memory leak
  powerpc/85xx: Fix SPE float to integer conversion failure
  powerpc/85xx: Update sata controller compatible for p1022ds board
  ATA: Add FSL sata v2 controller support
  powerpc/mpc8xxx_gpio: simplify searching for 'fsl, qoriq-gpio' compatiable
  powerpc/8xx: remove obsolete mgsuvd board
  powerpc/82xx: rename and update mgcoge board support
  powerpc/83xx: rename and update kmeter1
  powerpc/85xx: Workaroudn e500 CPU erratum A005
  powerpc/fsl_pci: Add support for FSL PCIe controllers v2.x
  powerpc/85xx: Fix writing to spin table 'cpu-release-addr' on ppc64e
  powerpc/pseries: Disable MSI using new interface if possible
  powerpc: Enable GENERIC_HARDIRQS_NO_DEPRECATED.
  powerpc: core irq_data conversion.
  powerpc: sysdev/xilinx_intc irq_data conversion.
  powerpc: sysdev/uic irq_data conversion.
  ...

Fix up conflicts in arch/powerpc/sysdev/fsl_msi.c (due to getting rid of
of_platform_driver in arch/powerpc)
2011-03-18 06:31:43 -07:00
Linus Torvalds
6899608533 Merge branch 'for-linus' of git://codeaurora.org/quic/kernel/davidb/linux-msm
* 'for-linus' of git://codeaurora.org/quic/kernel/davidb/linux-msm: (46 commits)
  msm: scm: Check for interruption immediately
  msm: scm: Fix improper register assignment
  msm: scm: Mark inline asm as volatile
  msm: iommu: Enable HTW L2 redirection on MSM8960
  msm: iommu: Don't read from write-only registers
  msm: iommu: Remove dependency on IDR
  msm: iommu: Use ASID tagging instead of VMID tagging
  msm: iommu: Rework clock logic and add IOMMU bus clock control
  msm: iommu: Clock control for the IOMMU driver
  msm: mdp: Set the correct pack pattern for XRGB/ARGB
  msm_fb: Fix framebuffer console
  msm: mdp: Add support for RGBX 8888 image format.
  video: msmfb: Put the partial update magic value into the fix_screen struct.
  msm: clock: Migrate to clkdev
  msm: clock: Remove references to clk_ops_pcom
  msm: headsmp.S: Fix section mismatch
  msm: Use explicit GPLv2 licenses
  msm: iommu: Enable IOMMU support for MSM8960
  msm: iommu: Generalize platform data for multiple targets
  msm: iommu: Create a Kconfig item for the IOMMU driver
  ...
2011-03-17 19:13:18 -07:00
Linus Torvalds
411f5c7a50 Merge branch 'devel-stable' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel-stable' of master.kernel.org:/home/rmk/linux-2.6-arm: (289 commits)
  davinci: DM644x EVM: register MUSB device earlier
  davinci: add spi devices on tnetv107x evm
  davinci: add ssp config for tnetv107x evm board
  davinci: add tnetv107x ssp platform device
  spi: add ti-ssp spi master driver
  mfd: add driver for sequencer serial port
  ARM: EXYNOS4: Implement Clock gating for System MMU
  ARM: EXYNOS4: Enhancement of System MMU driver
  ARM: EXYNOS4: Add support for gpio interrupts
  ARM: S5P: Add function to register gpio interrupt bank data
  ARM: S5P: Cleanup S5P gpio interrupt code
  ARM: EXYNOS4: Add missing GPYx banks
  ARM: S3C64XX: Fix section mismatch from cpufreq init
  ARM: EXYNOS4: Add keypad device to the SMDKV310
  ARM: EXYNOS4: Update clocks for keypad
  ARM: EXYNOS4: Update keypad base address
  ARM: EXYNOS4: Add keypad device helpers
  ARM: EXYNOS4: Add support for SATA on ARMLEX4210
  plat-nomadik: make GPIO interrupts work with cpuidle ApSleep
  mach-u300: define a dummy filter function for coh901318
  ...

Fix up various conflicts in
 - arch/arm/mach-exynos4/cpufreq.c
 - arch/arm/mach-mxs/gpio.c
 - drivers/net/Kconfig
 - drivers/tty/serial/Kconfig
 - drivers/tty/serial/Makefile
 - drivers/usb/gadget/fsl_mxc_udc.c
 - drivers/video/Kconfig
2011-03-17 19:08:06 -07:00
Linus Torvalds
6d7ed21d17 Merge branches 'defcfg', 'drivers' and 'cyberpro-next' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'defcfg' of master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: 6647/1: add Versatile Express defconfig
  ARM: 6644/1: mach-ux500: update the U8500 defconfig

* 'drivers' of master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: 6764/1: pl011: factor out FIFO to TTY code
  ARM: 6763/1: pl011: add optional RX DMA to PL011 v2
  ARM: 6758/1: amba: support pm ops
  ARM: amba: make amba_driver id_table const
  ARM: amba: make internal ID table handling const
  ARM: amba: make probe() functions take const id tables
  ARM: 6662/1: amba: make amba_bustype non-static
  ARM: mmci: add dmaengine-based DMA support
  ARM: mmci: no need for separate host->data_xfered
  ARM: mmci: avoid unnecessary switch to data available PIO interrupts
  ARM: mmci: no need to call flush_dcache_page() with sg_miter API
  ARM: mmci: avoid reporting too many completed bytes on fifo overrun
  ALSA: AACI: make fifo variables more explanitory
  ALSA: AACI: no need to call snd_pcm_period_elapsed() for each period
  ALSA: AACI: use snd_pcm_lib_period_bytes()
  ALSA: AACI: clean up AACI announcement printk
  ALSA: AACI: fix channel mask selection
  ALSA: AACI: fix number of channels for record
  ALSA: AACI: fix multiple IRQ claiming

* 'cyberpro-next' of master.kernel.org:/home/rmk/linux-2.6-arm:
  VIDEO: cyberpro: remove unused cyber2000fb_get_fb_var()
  VIDEO: cyberpro: remove useless function extreg pointers
  VIDEO: cyberpro: update handling of device structures
  VIDEO: cyberpro: add support for video capture I2C
  VIDEO: cyberpro: make 'reg_b0_lock' always present
  VIDEO: cyberpro: add I2C support
  VIDEO: cyberpro: select lowest multipler/divisor for PLL
2011-03-17 18:48:35 -07:00
Linus Torvalds
514af9f790 Merge branches 'stable/hvc-console', 'stable/gntalloc.v6' and 'stable/balloon' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/hvc-console' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/hvc: Disable probe_irq_on/off from poking the hvc-console IRQ line.

* 'stable/gntalloc.v6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: gntdev: fix build warning
  xen/p2m/m2p/gnttab: do not add failed grant maps to m2p override
  xen-gntdev: Add cast to pointer
  xen-gntdev: Fix incorrect use of zero handle
  xen: change xen/[gntdev/gntalloc] to default m
  xen-gntdev: prevent using UNMAP_NOTIFY_CLEAR_BYTE on read-only mappings
  xen-gntdev: Avoid double-mapping memory
  xen-gntdev: Avoid unmapping ranges twice
  xen-gntdev: Use map->vma for checking map validity
  xen-gntdev: Fix unmap notify on PV domains
  xen-gntdev: Fix memory leak when mmap fails
  xen/gntalloc,gntdev: Add unmap notify ioctl
  xen-gntalloc: Userspace grant allocation driver
  xen-gntdev: Support mapping in HVM domains
  xen-gntdev: Add reference counting to maps
  xen-gntdev: Use find_vma rather than iterating our vma list manually
  xen-gntdev: Change page limit to be global instead of per-open

* 'stable/balloon' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (24 commits)
  xen-gntdev: Use ballooned pages for grant mappings
  xen-balloon: Add interface to retrieve ballooned pages
  xen-balloon: Move core balloon functionality out of module
  xen/balloon: Remove pr_info's and don't alter retry_count
  xen/balloon: Protect against CPU exhaust by event/x process
  xen/balloon: Migration from mod_timer() to schedule_delayed_work()
  xen/balloon: Removal of driver_pages
2011-03-17 18:16:36 -07:00
Russell King
9c9585e0e9 Merge branches 'aaci', 'mmci-dma', 'pl' and 'pl011' into drivers 2011-03-17 11:04:51 +00:00
Paul Mundt
1d2a1959fe Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into sh-latest 2011-03-17 16:44:08 +09:00
David Brown
92c260f755 Merge remote branch 'rmk/for-linus' into for-linus
* rmk/for-linus: (1557 commits)
  ARM: 6806/1: irq: introduce entry and exit functions for chained handlers
  ARM: 6781/1: Thumb-2: Work around buggy Thumb-2 short branch relocations in gas
  ARM: 6747/1: P2V: Thumb2 support
  ARM: 6798/1: aout-core: zero thread debug registers in a.out core dump
  ARM: 6796/1: Footbridge: Fix I/O mappings for NOMMU mode
  ARM: 6784/1: errata: no automatic Store Buffer drain on Cortex-A9
  ARM: 6772/1: errata: possible fault MMU translations following an ASID switch
  ARM: 6776/1: mach-ux500: activate fix for errata 753970
  ARM: 6794/1: SPEAr: Append UL to device address macros.
  ARM: 6793/1: SPEAr: Remove unused *_SIZE macros from spear*.h files
  ARM: 6792/1: SPEAr: Replace SIZE macro's with SZ_4K macros
  ARM: 6791/1: SPEAr3xx: Declare device structures after shirq code
  ARM: 6790/1: SPEAr: Clock Framework: Rename usbd clock and align apb_clk entry
  ARM: 6789/1: SPEAr3xx: Rename sdio to sdhci
  ARM: 6788/1: SPEAr: Include mach/hardware.h instead of mach/spear.h
  ARM: 6787/1: SPEAr: Reorder #includes in .h & .c files.
  ARM: 6681/1: SPEAr: add debugfs support to clk API
  ARM: 6703/1: SPEAr: update clk API support
  ARM: 6679/1: SPEAr: make clk API functions more generic
  ARM: 6737/1: SPEAr: formalized timer support
  ...

Conflicts:
	arch/arm/mach-msm/board-msm7x27.c
	arch/arm/mach-msm/board-msm7x30.c
	arch/arm/mach-msm/board-qsd8x50.c
	arch/arm/mach-msm/board-sapphire.c
	arch/arm/mach-msm/include/mach/memory.h
2011-03-16 22:13:16 -07:00