This reverts commit 06aa82e4.
This commit purports to enable auto CTS flow control for the 8250
UART driver. However, the 8250 UART driver already supports auto
CTS flow control via UART_CAP_AFE and UART_CAP_EFR. Indeed, this
patch introduces another DT attribute for which an existing firmware
flag already exists ("auto-flow-control"). Furthermore, the use of
UPF_HARD_FLOW requires the UART driver to define .throttle and
.unthrottle methods, neither of which are defined for the 8250 UART
driver (which will result in a NULL ptr dereference). Finally, this patch
supposes to fix existing bugs in the serial core for auto CTS-enabled
hardware, but does not include the class of hardware for which these
bugs exist.

CC: Murali Karicheri <m-karicheri2@ti.com>
CC: Rob Herring <robh+dt@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Allow Samsung serial driver to be usable on Exynos 64-bit SoC based
platforms.
Signed-off-by: NPankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: NNaveen Krishna Chatradhi <ch.naveen@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Delete successive assignments to the same location.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression i;
@@

*i = ...;
 i = ...;
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix build failure caused by missing header file:

drivers/tty/serial/nwpserial.c: In function 'wait_for_bits':
drivers/tty/serial/nwpserial.c:53:3: error: implicit declaration of function 'udelay' [-Werror=implicit-function-declaration]
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The SoC has four fully functional UARTs which use the same programming
model. They are named UART_A, UART_B, UART_C and UART_AO (Always-On)
which cannot be powered off.
Signed-off-by: NCarlo Caione <carlo@caione.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Several architectures (e.g. microblaze, um, and score) have already have
extern 'setup_memory', so need use 'nozomi_setup_memory' instead of, or
will cause compiling issue.

The related error (with allmodconfig for microblaze):

  CC [M]  drivers/tty/nozomi.o
drivers/tty/nozomi.c:526:13: error: conflicting types for 'setup_memory'
 static void setup_memory(struct nozomi *dc)
             ^
In file included from include/linux/mm.h:51:0,
                 from ./arch/microblaze/include/asm/io.h:17,
                 from include/linux/io.h:22,
                 from include/linux/pci.h:31,
                 from drivers/tty/nozomi.c:46:
./arch/microblaze/include/asm/pgtable.h:569:6: note: previous declaration of 'setup_memory' was here
 void setup_memory(void);
      ^
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Acked-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need to init .owner field.

Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"

This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Acked-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need to init .owner field.

Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"

This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The symbol is defined in drivers/tty/serial/8250/Kconfig as
"SERIAL_8250", not just "8250".
Signed-off-by: NDaniele Forsi <dforsi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the N_TTY line discipline receives data and wakes readers to
process the input, polling writers are also mistakenly woken. This
is because, although readers and writers are differentiated by
different wait queues (tty->read_wait & tty->write_wait), both
wait queues are polled together. Thus, reader wakeups without poll
flags still cause poll(POLLOUT) to wakeup.

For received data, wakeup readers with POLLIN. Preserve the
unspecific wakeup in n_tty_packet_mode_flush(), as this action
should flag both POLLIN and POLLOUT.

Fixes epoll_wait() for edge-triggered EPOLLOUT.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In case if we're releasing the last tty reference the following
call sequence is possible

tty_driver_kref_put
  destruct_tty_driver
    kfree(driver);

where @driver is used in next module_put call, which leads to

 | [ 285.964007] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 | [ 285.964007] Workqueue: events release_one_tty
 | [ 285.964007] task: ffff8800cc7ea5f0 ti: ffff8800cb800000 task.ti: ffff8800cb800000
 | [ 285.964007] RIP: 0010:[<ffffffff810aeaf5>] [<ffffffff810aeaf5>] module_put+0x24/0xf4
 | [ 285.964007] RSP: 0018:ffff8800cb801d48 EFLAGS: 00010213
 | [ 285.964007] RAX: ffff8800cb801fd8 RBX: ffff8800ca3429d0 RCX: ffff8800cb1db400
 | [ 285.964007] RDX: 0000000000000000 RSI: ffffffff817349c1 RDI: 0000000000000001
 | [ 285.964007] RBP: ffff8800cb801d60 R08: ffff8800cd632b40 R09: 0000000000000000
 | [ 285.964007] R10: 00000000ffffffff R11: ffff88011f40a000 R12: 6b6b6b6b6b6b6b6b
 | [ 285.964007] R13: ffff8800ca342520 R14: 0000000000000000 R15: ffff88011f5d8200
 | [ 285.964007] FS: 0000000000000000(0000) GS:ffff88011f400000(0000) knlGS:0000000000000000
 | [ 285.964007] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 | [ 285.964007] CR2: 00007faf5229d090 CR3: 0000000001c0b000 CR4: 00000000000006f0
 | [ 285.964007] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 | [ 285.964007] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 | [ 285.964007] Stack:
 | [ 285.964007] ffff8800ca3429d0 ffff8800ca342a30 ffff8800ca342520 ffff8800cb801d88
 | [ 285.964007] ffffffff8146554a ffff8800cc77cc78 ffff8800ca3429d0 ffff88011f5d3800
 | [ 285.964007] ffff8800cb801e08 ffffffff810683c1 ffffffff810682ff 0000000000000046
 | [ 285.964007] Call Trace:
 | [ 285.964007] [<ffffffff8146554a>] release_one_tty+0x54/0xa3
 | [ 285.964007] [<ffffffff810683c1>] process_one_work+0x223/0x404
 | [ 285.964007] [<ffffffff810682ff>] ? process_one_work+0x161/0x404
 | [ 285.964007] [<ffffffff81068971>] worker_thread+0x136/0x205
 | [ 285.964007] [<ffffffff8106883b>] ? rescuer_thread+0x26a/0x26a
 | [ 285.964007] [<ffffffff8106e5bf>] kthread+0xa2/0xaa
 | [ 285.964007] [<ffffffff810a4586>] ? trace_hardirqs_on_caller+0x16/0x1eb
 | [ 285.964007] [<ffffffff8106e51d>] ? __kthread_parkme+0x65/0x65
 | [ 285.964007] [<ffffffff8173f59c>] ret_from_fork+0x7c/0xb0
 | [ 285.964007] [<ffffffff8106e51d>] ? __kthread_parkme+0x65/0x65
 | [ 285.964007] Code: 09 00 5b 41 5c 5d c3 0f 1f 44 00 00 55 48 85 ff 48 89 e5 41 55 41 54 49 89 fc 53 0f 84 d3 00
 | 00 00 bf 01 00 00 00 e8 d0 a1 fc ff <49> 8b 84 24 50 02 00 00 65 48 ff 40 08 4c 8b 6d 08 0f 1f 44 00

so simply keep a local reference to the module owner and
use it later.

CC: Pavel Emelyanov <xemul@parallels.com>
CC: Jiri Slaby <jslaby@suse.cz>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Frank reports that after continuing in kgdb the RX stale event
doesn't occur until after the RX fifo is filled up with exactly
the amount of characters programmed for the RX watermark (in this
case it's 48). To read a single character from the uartdm
hardware we force a stale event so that any characters in the RX
packing buffer are flushed into the RX fifo immediately instead
of waiting for a stale timeout or for the fifo to fill. Forcing
that stale event asserts the stale interrupt but we never clear
that interrupt via UART_CR_CMD_RESET_STALE_INT in the polling
functions. So when kgdb continues the stale interrupt is left
pending in the hardware and we don't timeout with a stale event,
like we usually would if a user typed one character on the
console, until the reset stale interrupt and stale event commands
are sent. Frank could get things working again by running
handle_rx_dm(). By putting enough characters into the fifo he
could trigger a watermark interrupt, and thus cause
handle_rx_dm() to run finally resetting the stale interrupt
and enabling the stale event so that single characters would
cause timeouts again.

The fix is to just do what the interrupt routine was doing all
along and clear the stale interrupt and enable the event again.
Doing this also smooths over any differences in the fifo behavior
between v1.3 and v1.4 hardware allowing us to skip forcing the
uart into single character mode.
Reviewed-by: NFrank Rowand <frank.rowand@sonymobile.com>
Tested-by: NFrank Rowand <frank.rowand@sonymobile.com>
Fixes: f7e54d7a "msm_serial: Add support for poll_{get,put}_char()"
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The prefix suggests the number should be printed in hex, so use
the %x specifier to do that.

Found by using regex suggested by Joe Perches.
Signed-off-by: NHans Wennborg <hans@hanshq.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CLPS711X serial driver uses the system wide registers to control the
modem signals. Now gpio-syscon driver can be used for this purposes.
mctrl_gpio helpers allow us to create GPIO bindings for any of modem/tty
control signals that extends the functionality of the driver.
This patch makes such change.

This change does not break any current DT bindings, since DT support
for this platform is not introduced yet.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

printk replaced with corresponding dev_* .
fixed two broken user-visible strings used by the corresponding printk.
the null check for uport->dev and port->dev is removed as dev_* will check for
null while printing.
printing of dev_name(uport->dev) and dev_name(port->dev) also removed as those
are being printed by dev_* .
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make the of_device_id arrays const, as it is handled as const by all OF
functions.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: void function return statements are not generally useful
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: else is not generally useful after a break or return
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then dev_info(dev, ... then pr_info(...  to printk(KERN_INFO ...
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes below checkpatch.pl warning and it remove extra blank lines:

WARNING: Missing a blank line after declarations
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fixed below checkpatch.pl warning:

WARNING: braces {} are not necessary for any arm of this statement
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch lets you set the RS485 cappabilites of the device through
TIOCSRS485 and TIOCGRS485 as defined on Documentation/serial/serial-rs485.txt

In order to probe the device, the PNP id and the device id is used.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch allow the users of the 8250 infrastructure to define a
handler for RS485 configration.

If no handler is defined the 8250 driver will work as usual.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
--
v2:Change suggested by Alan "One Thousand Gnomes":
- Move rs485 structure further down on the uart_8250_port structure

 drivers/tty/serial/8250/8250_core.c | 39 +++++++++++++++++++++++++++++++++++++
 include/linux/serial_8250.h         |  3 +++
 2 files changed, 42 insertions(+)
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add device ids for additional Neo cards.  The ids come from the dgnc
driver.
Signed-off-by: NBill Pemberton <wfp5p@worldbroken.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the now unnecessary memset too.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With memoryless node support being worked on, it's possible that for
optimizations that a node may not have a non-NULL zonelist.  When
CONFIG_NUMA is enabled and node 0 is memoryless, this means the zonelist
for first_online_node may become NULL.

The oom killer requires a zonelist that includes all memory zones for
the sysrq trigger and pagefault out of memory handler.

Ensure that a non-NULL zonelist is always passed to the oom killer.

[akpm@linux-foundation.org: fix non-numa build]
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix detection of BREAK on sunsab serial console: BREAK detection was only
performed when there were also serial characters received simultaneously.
To handle all BREAKs correctly, the check for BREAK and the corresponding
call to uart_handle_break() must also be done if count == 0, therefore
duplicate this code fragment and pull it out of the loop over the received
characters.

Patch applies to 3.16-rc6.
Signed-off-by: NChristopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If gsmld_attach_gsm fails, the gsm is not used anymore.
tty core will not call gsmld_close to do the cleanup work.
tty core just restore to the tty old ldisc.
That always causes memory leak.
Signed-off-by: Nxinhui.pan <xinhuiX.pan@intel.com>
Reported-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA is a function 0 of the multifunction device where SPI host is attached.
Thus, we may avoid to hardcode PCI slot number.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Just a simple cleanup of init_timer with setting the fields manually.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The s->clk never gets setup in sc16is7xx_probe() and instead was using a
local clk variable, but then testing the uninitialized s->clk during
teardown
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJon Ringle <jringle@gridpoint.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The 8250_dw driver fails to probe if the specified clock isn't
registered at probe time. Even if a clock frequency is given,
the required clock might be gated because it wasn't properly
enabled.

This happened to me when the device is registered through DT,
and the clock was part of an MFD, the PRCM found on A31 and A23
SoCs. Unlike core clocks that are registered with OF_CLK_DECLARE,
which happen almost immediately after the kernel starts, the
clocks are registered as sub-devices of the PRCM MFD platform
device. Even though devices are registered in the order they are
found in the DT, the drivers are registered in a different,
arbitrary order. It is possible that the 8250_dw driver is
registered, and thus associated with the device and probed, before
the clock driver is registered and probed.

8250_dw then reports unable to get the clock, and fails. Without
a working console, the kernel panics.

This patch adds support for deferred probe handling for the clock
and reset controller. It also fixes the cleanup path if
serial8250_register_8250_port fails.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Allwinner A31 and A23 SoCs have a reset controller
maintaining the UART in reset by default.

This patch adds optional reset support to the driver.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the current calculation, if the required baud rate is above 262143,
we get an overflow.

This patch uses a 64bits variable to do the maths.
Also, we remove the '+1' to avoid a divide by zero if the input clock
rate is something unexpected.
Indeed, if the input clock rate is zero, it is preferable to be notified,
since the UART won't work anyway.
Signed-off-by: NMaxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In order to prevent an asc instance to be used as early console, BUG_ON is
used on either mapbase or membase being NULL.

Problem is that this condition is also true when we set console to be a ttyASx
different to the first asc instance being probed.

Instead of calling BUG_ON, it now returns -ENXIO when either mapbase or
membase is NULL.
Signed-off-by: NMaxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make of_device_id array const, because all OF functions handle it as const.
Signed-off-by: NKiran Padwal <kiran.padwal@smartplayin.com>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

gsm->num is the index of gsm_mux[], it's invalid before calling gsm_activate_mux.
Signed-off-by: Nxinhui.pan <xinhuiX.pan@intel.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Current code allocates too much data for tty_groups member of uart_port struct,
so fix it.
Signed-off-by: NYoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

dma_{un}map_* uses 'enum dma_data_direction' not 'enum dma_transfer_direction'.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>