We need this helper to fix system stalls. The issue is that the rest
of the system TTYs wait for us to finish waiting. This wasn't an issue
with BKL. BKL used to unlock implicitly.

This is based on the Arnd suggestion.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

So now, when we handle CLOSING flag, there is no point to hold
port->mutex over the start of uart_close.

Yes, there are still several things to reason about:
* port->count etc is and always was protected by a spinlock
* ->stop_rx is protected by a spinlock. Otherwise it would
  race with interrupts.
* uart_wait_until_sent -- that one is already called without
  port->mutex from set_termios and tty_set_ldisc. Should anything
  be protected there, it would be tx_empty. And by a spinlock.
  8250 does this internally...

This step is needed to fix system stalls. To not create an AB-BA lock
dependency (see next patches).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

We need to move port->mutex locking after wait_until_sent in
uart_close (for rationale see next patches). But if we did it now, we
would introduce a race between close and open. This is exactly why
port->mutex is locked at the top of uart_close.

To avoid the race, we add ASYNCB_CLOSING to uart_close. Like every
other sane TTY driver. Thanks to tty_port_block_til_ready used in
uart_open we will have this for free. Then we can move the port->mutex
lock.

Also note that this will make the conversion to tty_port helpers
easier. They are currently handling ASYNC_CLOSING flag correctly.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Instead of printing the head of the buffer, we should print the tail,
which is the byte we are sending to the device.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

jsm uses a write queue that copies from uart_core circular buffer. This
copying however has some bugs, like not wrapping the head counter. Since
this write queue is also a circular buffer, the consumer function is
ready to use the uart_core circular buffer directly.

This buggy copying function was making some bytes be dropped when
transmitting to a raw tty, doing something like this.

[root@hostname ~]$ cat /dev/ttyn1 > cascardo/dump &
[1] 2658
[root@hostname ~]$ cat /proc/tty/drivers > /dev/ttyn0
[root@hostname ~]$ cat /proc/tty/drivers
/dev/tty             /dev/tty        5       0 system:/dev/tty
/dev/console         /dev/console    5       1 system:console
/dev/ptmx            /dev/ptmx       5       2 system
/dev/vc/0            /dev/vc/0       4       0 system:vtmaster
jsm                  /dev/ttyn     250 0-31 serial
serial               /dev/ttyS       4 64-95 serial
hvc                  /dev/hvc      229 0-7 system
pty_slave            /dev/pts      136 0-1048575 pty:slave
pty_master           /dev/ptm      128 0-1048575 pty:master
unknown              /dev/tty        4 1-63 console
[root@hostname ~]$ cat cascardo/dump
/dev/tty             /dev/tty        5       0 system:/dev/tty
/dev/console         /dev/console    5       1 system:console
/dev/ptmx            /dev/ptmx       5       2 system
/dev/vc/0            /dev/vc/0       4       0 system:vtmaste[root@hostname ~]$

This patch drops the driver write queue entirely, using the circular
buffer from uart_core only.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The flip buffer is not used anymore. Remove its allocation and
declaration in the board structure.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

According to add support EXYNOS4212 SoC, we need to enable
SERIAL_S5PV210 on EXYNOS4212.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

By default the atmel_serial driver in RS485 mode disables receiving data until
all data in the send buffer has been sent. This flag allows to receive data
even whilst sending data.
Signed-off-by: Bernhard Roth <br@pwrnet.de>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The imx UART hardware controller can identify BREAK character and the
imx_set_termios() can accept BRKINT set by users, but current existing
imx_rxint() can't pass BREAK character and TTY_BREAK to the tty layer
as other serial drivers do (8250.c omap_serial.c).

Here add code to handle BREAK character and pass it to tty layer.

To detect error occurrence, i use URXD_ERR to replace (URXD_OVRRUN |
URXD_FRMERR | ...) because any kind of error occurs, URXD_ERR will
always be set to 1.

I put the URXD_BRK to the first place to check since when BREAK error
occurs, not only URXD_BRK is set to 1, but also URXD_PRERR and
URXD_FRMERR are all set to 1. This arrangement can filter out fake
parity and frame errors when BREAK error occurs.
Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This reverts commit 6b1a98d1.

It causes a build error that needs to be resolved differently.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This reverts commit 14a8d47d.

It causes a build error that needs to be resolved differently.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Support the DesignWare 8250 by a new compatible string and registering
the DesignWare helpers.  If the registration of the helpers fails, then
continue as a normal 8250 as we may still get some useful debug out.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The Synopsys DesignWare 8250 is an 8250 that has an extra interrupt that
gets raised when writing to the LCR when busy.  To handle this we need
special serial_out, serial_in and handle_irq methods.  Add a new
function serial8250_use_designware_io() that configures a uart_port with
these accessors.

Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Now that platforms can override the port IRQ handler and the only user
of these UPIO modes has been converted over, kill off UPIO_DWAPB and
UPIO_DWAPB32.
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The Synopsys DesignWare UART in pmc-sierra msp71xx has an extra feature
where the UART detects a write attempt to the LCR whilst busy and raises
an interrupt.  The driver needs to clear the interrupt and rewrite the
LCR.  Move this into platform code and out of the 8250 driver.
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Convert to pr_foo() helpers rather than printk(KERN_.*).
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Anoop P A<Anoop_P.A@pmc-sierra.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Some ports (e.g. Synopsys DesignWare 8250) have special requirements for
handling the interrupts.  Allow these platforms to specify their own
interrupt handler that will override the default.
serial8250_handle_irq() is provided so that platforms can extend the IRQ
handler rather than completely replacing it.
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Some serial ports may have unusal requirements for interrupt handling
(e.g. the Synopsys DesignWare 8250-alike port and it's busy detect
interrupt).  Add a .handle_irq callback that can be used for platforms
to override the interrupt behaviour in a similar fashion to the
.serial_out and .serial_in callbacks.
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

With uart tx/rx/err interrupt handling moved into the driver for s3c64xx
and later SoC's, the uart interrupt handling in plaform code can be removed.
The uart device irq resources is reduced to one and the related unused
macros are removed.
Suggested-by: Grant Likely <grant.likely@secretlab.ca>
CC: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

s3c64xx and later SoC's include the interrupt mask and pending registers
in the uart controller, unlike the s3c24xx SoC's which have these registers
in the interrupt controller. When the mask and pending registers are part
of the uart controller, a unified interrupt handler can handle the tx/rx
interrupt. With this, the static reservation of interrupt numbers for the
uart tx/rx/err interrupts in the linux irq space is not required and
simplifies adding device tree support.
Suggested-by: Grant Likely <grant.likely@secretlab.ca>
CC: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Serial TX IRQ is not RX IRQ plus 1 in some blackfin chips.
Give individual platform resources to both TX and RX irqs.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Even though this is valid C we should not mix C99 initializers with
obfuscated ANSI C. Stick to C99 and initialize c by its name.

Found by clang:
drivers/tty/vt/vt.c:262:55: warning: explicitly assigning a variable of
type 'unsigned int' to itself [-Wself-assign]
    struct vt_notifier_param param = { .vc = vc, unicode = unicode };
                                                 ~~~~~~~ ^ ~~~~~~~
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

bfin_5xx.c is not a general name for all Blackfin chips.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

It makes the code really ugly. And since it can be enabled only before
building and only in the source files, it can be barely used by users.
That said, I've not seen anybody to use it in the past few years.

This crap is copied to some more drivers over the tty tree. Since I'm
not their maintainer, I'm not sure if I should remove them too?
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

We used it really only serial and ami_serial. The rest of the
callsites were BUG/WARN_ONs to check if BTM is held. Now that we
pruned tty_locked from both of the real users, we can get rid of
tty_lock along with __big_tty_mutex_owner.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The same as in "TTY: serial, remove BTM from wait_until_sent" we don't
need to take BTM in wait_until_sent of ami_serial. Exactly the same
as serial, ami_serial accesses some "info" members (xmit_fifo_size,
timeout), but their assignment on other places in the code is not
protected by BTM anyway.

So the BTM protects nothing here. This removal helps us to get rid of
tty_locked() and __big_tty_mutex_owner in the following patch. This
was suggested by Arnd.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Andreas Bombe <aeb@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

tty_wakeup can be called from any context. So there is no need to have
an extra tasklet for calling that. Hence save some space and remove
the tasklet completely.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

It doesn't make sense to set console to uart_port in console->setup.
At that time the console is set by uart_add_one_port already.

The call chain looked like:
uart_add_one_port()
  uport->cons = drv->cons;   <= once
  uart_configure_port()
    register_console()
     console->setup()
       port->cons = co;      <= second time
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

During the BKL removal process, the BKL was switched to tty_lock
(BTM). Now we should start pruning the BTM further. Let's start with
wait_until_sent of the serial layer. This will allow us to switch to
the tty port helpers and thus clean it up much.

In wait_until_sent there are some uport members accessed, but neither
of them is protected by BTM at the location they are set ('=>' means
function call):
* uport->fifosize (set in tty_ioctl => uart_ioctl => uart_set_info)
* uport->type (set in add_one_port prior to tty_register_device)
* uport->timeout (set usually in tty_ioctl => tty_mode_ioctl =>
  tty_set_termios => uart_set_termios => uart_change_speed =>
  uport->ops->set_termios => uart_update_timeout)
* call to uport->ops->tx_empty()

If the tx_empty hook needs some lock to protect accesses to registers,
it should take &uport->lock spinlock like 8250 does. Otherwise there
still might be races e.g. with ISRs.

This should also fix the issue Andreas is seeing (BTM in comparison to
BKL doesn't have any hidden functionality like unlocking during
sleeping).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
References: https://lkml.org/lkml/2011/5/25/562
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andreas Bombe <aeb@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Redundant comment line was removed
Signed-off-by: Edwin van Vliet <edwin@cheatah.nl>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The ePAPR embedded hypervisor specification provides an API for "byte
channels", which are serial-like virtual devices for sending and receiving
streams of bytes.  This driver provides Linux kernel support for byte
channels via three distinct interfaces:

1) An early-console (udbg) driver.  This provides early console output
through a byte channel.  The byte channel handle must be specified in a
Kconfig option.

2) A normal console driver.  Output is sent to the byte channel designated
for stdout in the device tree.  The console driver is for handling kernel
printk calls.

3) A tty driver, which is used to handle user-space input and output.  The
byte channel used for the console is designated as the default tty.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Add group event scheduling option to perf record/stat
  MAINTAINERS: Fix list of perf events source files
  perf tools: Fix build against newer glibc
  perf tools: Fix error handling of unknown events
  perf evlist: Fix missing event name init for default event
  perf list: Fix exit value

* 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/tracing: Fix tracing config option properly
  xen: Do not enable PV IPIs when vector callback not present
  xen/x86: replace order-based range checking of M2P table by linear one
  xen: xen-selfballoon.c needs more header files

Steven Rostedt says we should use CONFIG_EVENT_TRACING.

Cc:Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Fix regression for HVM case on older (<4.1.1) hypervisors caused by

  commit 99bbb3a8
  Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  Date:   Thu Dec 2 17:55:10 2010 +0000

    xen: PV on HVM: support PV spinlocks and IPIs

This change replaced the SMP operations with event based handlers without
taking into account that this only works when the hypervisor supports
callback vectors. This causes unexplainable hangs early on boot for
HVM guests with more than one CPU.

BugLink: http://bugs.launchpad.net/bugs/791850

CC: stable@kernel.org
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-and-Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: core: handle ack_busy when fetching the Config ROM

This fixes a regression introduced by commit cdcb725c ("Btrfs: check
if there is enough space for balancing smarter").  We can't do 64-bit
divides on 32-bit architectures.

In cases where we need to divide/multiply by 2 we should just left/right
shift respectively, and in cases where theres N number of devices use
do_div.  Also make the counters u64 to match up with rw_devices.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Acked-and-tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: flush any pending end_io requests before DIO reads w/dioread_nolock
  ext4: fix nomblk_io_submit option so it correctly converts uninit blocks
  ext4: Resolve the hang of direct i/o read in handling EXT4_IO_END_UNWRITTEN.
  ext4: call ext4_ioend_wait and ext4_flush_completed_IO in ext4_evict_inode
  ext4: Fix ext4_should_writeback_data() for no-journal mode