Commit 19e2ad6a ("n_tty: Remove overflow
tests from receive_buf() path") moved the increment of read_head into
the arguments list of read_buf_addr(). Function calls represent a
sequence point in C. Therefore read_head is incremented before the
character c is placed in the buffer. Since the circular read buffer is
a lock-less design since commit 6d76bd26
("n_tty: Make N_TTY ldisc receive path lockless"), this creates a race
condition that leads to communication errors.

This patch modifies the code to increment read_head _after_ the data
is placed in the buffer and thus fixes the race for non-SMP machines.
To fix the problem for SMP machines, memory barriers must be added in
a separate patch.
Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds suspend/resume support for the of-serial driver
to provide power management support on devices attatched.

The handling may vary since not every of_serial device is
an 8250 port. Currently only 8250 port handling is added
in the suspend/resume function based on the type switch.
Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Joseph Lo <josephl@nvidia.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Florina Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 2dea53bf.

Turns out to be broken :(

Cc: Jingchang Lu <jingchang.lu@freescale.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 513e4385.

It's broken :(

Cc: Jingchang Lu <jingchang.lu@freescale.com>
Cc: Joseph Lo <josephl@nvidia.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Attempting to use SysRq via the 8250 serial port with spin lock
debugging on on a uniprocessor system results in the following splat:

 SysRq :
 BUG: spinlock trylock failure on UP on CPU#0, swapper/0
  lock: serial8250_ports+0x0/0x8c0, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0
 CPU: 0 PID: 0 Comm: swapper Not tainted 3.18.0-rc4+ #37
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
  ffffffff8245ba00 ffffffff81628b28 ffffffff812c8d27 ffffffff81628b48
  ffffffff8106812e ffffffff8245ba00 ffffffff814e22ed ffffffff81628b68
  ffffffff810681a6 0000000000000000 0000000000000000 ffffffff81628b88
 Call Trace:
  <IRQ>  [<ffffffff812c8d27>] dump_stack+0x19/0x1b
  [<ffffffff8106812e>] spin_dump+0x7e/0xd0
  [<ffffffff810681a6>] spin_bug+0x26/0x30
  [<ffffffff8106843c>] do_raw_spin_trylock+0x4c/0x60
  [<ffffffff812cdb1d>] _raw_spin_trylock+0x1d/0x60
  [<ffffffff812336d8>] serial8250_console_write+0x68/0x190
  [<ffffffff811eb0b0>] ? sprintf+0x40/0x50
  [<ffffffff8106ab5e>] call_console_drivers.constprop.11+0x9e/0xf0
  [<ffffffff8106b276>] console_unlock+0x3e6/0x490
  [<ffffffff8106b595>] vprintk_emit+0x275/0x530
  [<ffffffff812c869a>] printk+0x4d/0x4f
  [<ffffffff8121e612>] __handle_sysrq+0x62/0x1b0
  [<ffffffff8121e5b5>] ? __handle_sysrq+0x5/0x1b0
  [<ffffffff8121ebc6>] handle_sysrq+0x26/0x30
  [<ffffffff81233157>] serial8250_rx_chars+0x1d7/0x250
  [<ffffffff812338bb>] serial8250_handle_irq+0x7b/0x90
  [<ffffffff812338f3>] serial8250_default_handle_irq+0x23/0x30
  [<ffffffff812318b3>] serial8250_interrupt+0x63/0xe0
  [<ffffffff8106d80e>] handle_irq_event_percpu+0x4e/0x200
  [<ffffffff8106da01>] handle_irq_event+0x41/0x70
  [<ffffffff810701ee>] ? handle_edge_irq+0x1e/0x110
  [<ffffffff8107026e>] handle_edge_irq+0x9e/0x110
  [<ffffffff810041c2>] handle_irq+0x22/0x40
  [<ffffffff812d096e>] do_IRQ+0x4e/0xf0
  [<ffffffff812cf4ed>] common_interrupt+0x6d/0x6d
  <EOI>  [<ffffffff8100acbf>] ? default_idle+0x1f/0xd0
  [<ffffffff8100acbd>] ? default_idle+0x1d/0xd0
  [<ffffffff8100b61f>] arch_cpu_idle+0xf/0x20
  [<ffffffff8105c1db>] cpu_startup_entry+0x25b/0x360
  [<ffffffff812c726e>] rest_init+0xbe/0xd0
  [<ffffffff816a4dcb>] start_kernel+0x339/0x346
  [<ffffffff816a4495>] x86_64_start_reservations+0x2a/0x2c
  [<ffffffff816a4589>] x86_64_start_kernel+0xf2/0xf6
 HELP : loglevel(0-9) reboot(b) crash(c) show-all-locks(d) te...

Before ebade5e8 ("serial: 8250: Clean up the locking for -rt")
this was handled by not even attempting to try the lock if port->sysrq,
since it is known to be taken by the interrupt handler; see
https://bugzilla.kernel.org/show_bug.cgi?id=6716#c1.  Restore that
behavior.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since most drivers interpret UPIO_MEM32 to mean "little-endian" and use
readl/writel to access the registers, add a parallel UPIO_MEM32BE to
request the use of big-endian MMIO accessors (ioread32be/iowrite32be).
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Hardcoded FIFO size can cause hardware performance limitation.
Using real size value provides better FIFO usage.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If we have fifosize set in driver data we prefer to use it instead of default
fifosize value (which is always 16). If there is defined fifosize for particular
serial we prefer to use it, otherwise we use value from info, which is
common for all serials on given platform.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Split lines longer than 80 chars and remove unnecessary whitespaces.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds waiting until transmit buffer and shifter will be empty
before clock disabling.

Without this fix it's possible to have clock disabled while data was
not transmited yet, which causes unproper state of TX line and problems
in following data transfers.

Cc: <stable@vger.kernel.org> # v2.6.26+
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Return a negative error code on failure.

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

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty break and error flags are not bit masks so do not to use bitwise
OR when assigning them.

Note that there is no functional change due to the if-else construct and
flag having been initialised to zero (TTY_NORMAL).
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The original driver fixed the io address with 0xe000+idx*8,
but real io address assigned from BIOS is dynamically from
read PCI configure space 0x24, 0x20, 0x1c.

The Fintek F81504/F81508/F81512 maybe malfunction without
this patch and malfunction surely when more then 1 PCI card.
Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tx_empty() should test whether both the transmitter fifo and shifter
for the port is empty, ie. the whole last char was transmitted.
The shift register is empty if AUART_STAT_BUSY is cleared.
The patch fixes the function against the shift register.

According to i.MX23 and i.MX28 Reference Manual:
AUART_STAT_TXFE:
 TX FIFO or transmit holding register is empty.

AUART_STAT_BUSY:
 AUART still transmits bits.
 The BUSY signal goes HIGH as soon as the data is written to the
 transmit FIFO (that is, the FIFO is non-empty) and remains asserted
 HIGH while data is being transmitted.
 BUSY is negated only when the transmit FIFO is empty, and the last
 character has been transmitted from the shift register, including
 the stop bits.
Signed-off-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxs_auart_modem_status() did't detect gpio's state change
because s->mctrl_prev was modified before by mctrl_gpio_get().
The patch introduces mctrl_temp variable to fix the bug.
Signed-off-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 732a84a0 ("serial: core: Pass termios to set_ldisc() notifications")
changed the set_ldisc prototype.

At the time of this commit the mxs_auart driver did not implement set_ldisc,
so that's why it has not been converted.

Adapt also mxs_auart_set_ldisc() so that the following build warning can be
fixed:

drivers/tty/serial/mxs-auart.c:962:2: warning: initialization from
incompatible pointer type
  .set_ldisc      = mxs_auart_set_ldisc,
  ^
drivers/tty/serial/mxs-auart.c:962:2: warning: (near initialization
for 'mxs_auart_ops.set_ldisc')
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Although the existing code appears to work on most hardware, the
hardware designers tell us that 8-bit access to the registers is not
guaranteed to be reliable.  Also the OCTEON simulation environments
prohibit 8-bit accesses.

For these reasons, we use __raw_readq/__raw_writeq for OCTEON.  This
code is protected with #ifdef CONFIG_64BIT so it still builds under
configurations lacking readq/writeq.

We can get rid of the #ifdef __BIG_ENDIAN, as under 64-bit accesses,
OCTEON is byte order invariant.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When CONFIG_SERIAL_IMX_CONSOLE=n and CONFIG_CONSOLE_POLL=y we get the following
build warning:

drivers/tty/serial/imx.c:306:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:315:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]

imx_port_ucrs_save/restore are only used under CONFIG_SERIAL_IMX_CONSOLE, so
their definitions should be also be protected only by CONFIG_SERIAL_IMX_CONSOLE.

This was detected when building 'allmodconfig'.
Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

struct bfin_serial_port contains structs circ_buf, timer_list, and
work_struct directly (not pointers). This means that these structures
have to be defined completely to be inlined in struct
bfin_serial_port.

So instead of struct declarations, define the structures by including
proper headers. They were pulled in by linux/serial_core.h or others
until now. But experimenting with circ_buf removal from serial_core,
struct circ_buf becomes undefined in bfin_serial:

In file included from arch/blackfin/kernel/debug-mmrs.c:21:0:
arch/blackfin/include/asm/bfin_serial.h:44:18: error: field 'rx_dma_buf' has incomplete type
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Dan Carpenter reported:
|drivers/tty/serial/8250/8250_omap.c:1025 omap8250_probe()
|warn: unsigned 'up.port.line' is never less than zero.
|1025          if (up.port.line < 0) {

Since of_alias_get_id() and pdev->id can get negative I check for the
error via ret variable.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Dan Carpenter reported:
|drivers/tty/serial/8250/8250_omap.c:1025 omap8250_probe()
|warn: unsigned 'up.port.line' is never less than zero.
|1025          if (up.port.line < 0) {

I (wrongly) assumed that line is an int and compiler didn't complain nor
did sparse. Since of_alias_get_id() and pdev->id can get negative I
check for the error via ret variable.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The mcb_device_id table is supposed to be zero-terminated.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

in CSR A7DA SoC, uart6 located at BT module and it need multiple clock
sources, so for "sirf,marco-bt-uart" compatible uarts, drivers take 3
clock sources and enable them.

this patch also replaces clk_get by devm_clk_get function and fix DT
binding document in which we missed to fix when we added marco platform
in commit 909102db "serial: sirf: add support for Marco chip".
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert the pr_warning to the more common pr_warn.

Other miscellanea:

o Convert unusual PR_FMT define and uses to pr_fmt
o Remove unnecessary OOM message
o Fix grammar in an error message
o Convert a pr_warning with a KERN_ERR to pr_err
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit deals with the checkpatch warning "Unnecessary space before
function pointer arguments".
Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The changed function flushes the tx UART and the '4' corresponds to the
UART_FCR_CLEAR_XMIT value. This commit replaces the magic number with
this define.
Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit fixes the alignment of the 'case's i the switch statement.
Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The flow of {neo,cls}_param() shows that at this stage the baud rate
has a non-zero value. This fact makes the if clausule obsolete and
acknowledges it's removal.
Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The 'force' parameter to the {cls,neo}_send_break() function has been
removed because it has not been used. The client to this API (the tty
code) always called this function with only one value.
Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This changes negative values of error rate to be checked, because these
values are valid as error rate. And this changes in the process of adopting
a value close to 0.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Simply document the new compat string (and keep the list sorted by SoC).
There appears to be no need for a driver update.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Simply document the new compat string.
There appears to be no need for a driver update.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
[geert: Reworded to match previous commits]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Update devicetree binding for msm_serial to reflect msm_serial_probe()
getting line id (port number) from the serialN alias.
Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If there isn't a DT alias then of_alias_get_id() will return
-ENODEV. This will cause the msm_serial driver to fail probe,
when we want to keep the previous behavior where we generated a
dynamic line number at probe time. Restore this behavior by
generating a dynamic id if the line number is still negative
after checking for an alias or in the non-DT case looking at the
.id field of the platform device.
Reported-by: Kevin Hilman <khilman@kernel.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 68952076 ("vt: Remove
vt_get_kmsg_redirect() from uapi header") fails to compile if
!CONFIG_VT_CONSOLE.

Move macro definition for vt_get_kmsg_redirect() up with file-scope
function declarations.
Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 1bd83245.

To quote Olof:
	This commit broke a whole lot of tegra boards in last night's
	-next here. In particular, I've been looking at
	tegra20-seaboard, which now doesn't boot with console any more.

Breaking existing systems is bad.
Reported-by: Olof Johansson <olof@lixom.net>
Cc: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This resolves a merge issue with drivers/tty/serial/8250/8250_mtk.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull arm64 fixes from Catalin Marinas:
 - enable bpf syscall for compat
 - cpu_suspend fix when checking the idle state type
 - defconfig update

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: defconfig: update defconfig for 3.18
  arm64: compat: Enable bpf syscall
  arm64: psci: fix cpu_suspend to check idle state type for index

Pull ARM SoC fixes from Olof Johansson:
 "Another quiet week:

   - a fix to silence edma probe error on non-supported platforms from
     Arnd
   - a fix to enable the PL clock for Parallella, to make mainline
     usable with the SDK.
   - a somewhat verbose fix for the PLL clock tree on VF610
   - enabling of SD/MMC on one of the VF610-based boards (for testing)
   - a fix for i.MX where CONFIG_SPI used to be implicitly enabled and
     now needs to be added to the defconfig instead
   - another maintainer added for bcm2835: Lee Jones"

* tag 'armsoc-for-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: zynq: Enable PL clocks for Parallella
  dma: edma: move device registration to platform code
  ARM: dts: vf610: add SD node to cosmic dts
  MAINTAINERS: update bcm2835 entry
  ARM: imx: Fix the removal of CONFIG_SPI option
  ARM: imx: clk-vf610: define PLL's clock tree