Three UART drivers (8250, atmel & amba-pl010) directly call their
enable_ms() method; the uart port lock must be acquired before
any h/w programming.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

UART drivers which enable modem status interrupts when switching
to N_PPS line discipline need to determine if modem status
interrupts should be disabled when switching from N_PPS.
Specifically, the set_ldisc() notification needs to evaluate
UART_ENABLE_MS() which requires termios->c_cflag.

Convert in-tree UART drivers to new interface.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Three UART drivers (8250, atmel & amba-pl010) enable modem status
interrupts if the line discipline is changed to N_PPS. However,
the uart port flags may only be safely modified while holding the
port mutex.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Allow a tty driver to safely access termios settings while handling
the set_ldisc() notification. UART drivers use the set_ldisc()
notification to check if the N_PPS line discipline is being enabled;
if so, modem status interrupts may also need to be enabled. Conversely,
modem status interrupts may need to be disabled if switching away
from the N_PPS line discipline.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The line discipline buffer and the tty buffers must be flushed again
after hardware shutdown; otherwise, a brief window exists between the
ldisc flush in tty_port_close_start() and the subsequent
tty_port_shutdown(), during which more data could be received into the
tty buffers. A racing open might then be able to receive data from the
previous session.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tty->closing is a bitfield member; prevent corruption from non-atomic
update by assigning a unique memory location.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The port->lock does not protect the filp->f_op field; move
the tty_hung_up_p() test outside the port->lock critical section
in tty_port_close_start().
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for setting the state of the DTR and RTS signals.
Acked-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Get index of serial line from device tree using function of_alias_get_id().
If no alias is found, the 8250 core takes care of incrementing the line number.
Signed-off-by: NJulien CHAUVEAU <julien.chauveau@neo-technologies.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The general agreed way to specify a fixed line number
for a serial console is to provide a "serial" alias
in the devicetree. Start parsing this property in
of_serial.
Signed-off-by: NLucas Stach <dev@lynxeye.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check the return value of ioremap_nocache to make sure we got a
valid mapping.
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Several init/setup functions passed the PCI BAR resource start address
to ioremap_nocache() via an unsigned long. This caused address truncation
for a 32-bit device mapped above 4 GiB (i.e. the CPU interacts with the
device via a translated address), which resulted in a kernel panic.

This patch replaces all of the instances of intermediate variable use
with pci_ioremap_bar() to ensure the full resource_size_t start address
is used and that ioremap_nocache() is still called.

The kernel panic (Exar XR17V358 PCIe device on a Freescale P2020 SBC):

Machine check in kernel mode.
Caused by (from MCSR=10008): Bus - Read Data Bus Error
Oops: Machine check, sig: 7 [#1]
SMP NR_CPUS=2 X-ES P2020
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.14.15-xes_r2-00002-g560e401 #978
task: bf850000 ti: bffee000 task.ti: bf84c000
NIP: 80318e10 LR: 80319ecc CTR: 80318dfc
REGS: bffeff10 TRAP: 0204   Not tainted  (3.14.15-xes_r2-00002-g560e401)
MSR: 00021000 <CE,ME>  CR: 20adbe42  XER: 00000000
DEAR: c1058001 ESR: 00000000
GPR00: 00000000 bf84db30 bf850000 80cb4af8 00000001 00000000 80000007 80000000
GPR08: bf837c9c c1058001 00000001 00000000 80000007 00000000 80002a10 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 80cb0000 80c72dc4
GPR24: 80cb4900 fffffffe 00029000 00000001 bf8c11e8 ffffffea 80c72ce4 80cb4af8
NIP [80318e10] mem_serial_in+0x14/0x28
LR [80319ecc] serial8250_config_port+0x160/0xe38
Call Trace:
[bf84db30] [80319d94] serial8250_config_port+0x28/0xe38 (unreliable)
[bf84db60] [80315e3c] uart_add_one_port+0x148/0x3a4
[bf84dbf0] [8031bf40] serial8250_register_8250_port+0x2dc/0x3c8
[bf84dc20] [8032111c] pciserial_init_ports+0xd4/0x1c0
[bf84dd50] [803212f8] pciserial_init_one+0xf0/0x224
[bf84dd90] [802d8ff4] local_pci_probe+0x34/0x8c
[bf84dda0] [802d92c8] pci_device_probe+0x84/0xa0
[bf84ddc0] [80329ee0] driver_probe_device+0xac/0x26c
[bf84dde0] [8032a15c] __driver_attach+0xbc/0xc0
[bf84de00] [80328388] bus_for_each_dev+0x90/0xcc
[bf84de30] [80329cd0] driver_attach+0x24/0x34
[bf84de40] [80328e28] bus_add_driver+0x104/0x1fc
[bf84de60] [8032a8c8] driver_register+0x70/0x138
[bf84de70] [802d93c0] __pci_register_driver+0x48/0x58
[bf84de80] [8077e0e4] serial_pci_driver_init+0x24/0x34
[bf84de90] [80002228] do_one_initcall+0x34/0x1b0
[bf84df00] [80764294] kernel_init_freeable+0x138/0x1e8
[bf84df30] [80002a24] kernel_init+0x14/0x108
[bf84df40] [8000ef94] ret_from_kernel_thread+0x5c/0x64
Instruction dump:
800800c4 7d290214 39290001 7c0004ac 7ca049ae 7c0004ac 4e800020 88030035
81230008 7c840030 7d292214 7c0004ac <88690000> 0c030000 4c00012c 5463063e
---[ end trace e3c16443b5d573c6 ]---
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds 32-bit register lpuart32 power management support,
this also updates the 8-bit register lpuart resume function.
Signed-off-by: NJingchang Lu <jingchang.lu@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We are removing the dmaengine_device_control API, that shouldn't even have been
exposed in the first place. Change the callers to use the proper API.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In mtk8250_set_termios function, calculating quot value can not be zero,
otherwise, using DIV_ROUND_CLOSEST(port->uartclk, quot * baud) will fail due to
divisor is zero.
Signed-off-by: NEddie Huang <eddie.huang@mediatek.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

I wrote this driver and use it daily on several machines for work, so
why not.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We don't really need to perform the ioremap "on demand" so it's simpler
just to do it from the probe function.  This also lets us eliminate the
UART_REG_SIZE constant and rely on the resource information passed in
from the DT or platform code.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This enables early console output if there is a chosen/stdout-path
property referencing a UART node with the "brcm,bcm6345-uart" compatible
string.  The bootloader sets up the pinmux and baud/parity/etc.
Tested on bcm3384 (MIPS, DT).
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This squashes a checkpatch warning on my new bcm3384 dts submission.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the extra '<' character.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove incorrect "bcm963xx_uart" module name; add a list of known users;
tweak grammar/indentation/capitalization.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The original non-DT bcm63xx clk code ignores the struct device argument
and looks up a global clock name.  DT platforms, by contrast, often just
use a phandle to reference a clock node with no "clock-output-names"
property.  Modify the UART driver to support both schemes.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This device was originally supported on bcm63xx only, but it shows up on
a wide variety of MIPS and ARM chipsets spanning multiple product lines.
Now that the driver has eliminated dependencies on bcm63xx-specific
header files, we can build it on any non-bcm63xx kernel.

Compile-tested on x86, both statically and as a module.  Tested for
functionality on bcm3384 (a new MIPS platform under active development).
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For the console poll usage, .poll_init() will perform deeper hardware
initialization to ensure the serial port is always active.
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

imx_put_poll_char() has been simplified to remove the code to disable
interrupts. The present code can corrupt register state when re-entered
from FIQ handler.

Switch to _relaxed() MMIO functions (which are safe for polled I/O and
needed to avoid taking spin locks).
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We rely on probe order of this driver to determine the line number for
the uart port. This makes it impossible to know the line number
when these devices are populated via DT. Use the DT alias
mechanism to assign the line based on the aliases node.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to issue a reset if we ever change the value of the IPR
register on DM hardware. If we don't reset the hardware the RX
stale interrupt never triggers and the only way to trigger an RX
handling event is by filling up the fifo. This causes things like
getty to not work so well considering it might change the baud
rate a few times. Fix this by moving the reset on startup and any
reprogramming required after the reset to be after we change the
baud rate.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To properly support sysrq on uartDM hardware we need to properly
handle break characters. With the DM hardware the fifo can pack 4
characters at a time, where a break is indicated by an all zero
byte. Unfortunately, we can't differentiate between an all zero
byte for a break and an all zero byte of data, so try and do as
best we can. First unmask the RX break start interrupt and record
the interrupt when it arrives. Then while processing the fifo,
detect the break by searching for an all zero character as long
as we recently received an RX break start interrupt. This should
make sysrq work fairly well.

Cc: Frank Rowand <frank.rowand@sonymobile.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The handle_rx() path calls uart_handle_sysrq_char() with the port
lock held. This causes a spinlock recursion. Release and
reacquire the lock here to avoid this.

BUG: spinlock recursion on CPU#0, swapper/0
 lock: msm_uart_ports+0x1e0/0x2d0, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0
CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-rc7-00012-gb38ee8265941 #69
[<c0013964>] (unwind_backtrace) from [<c0011f74>] (show_stack+0x10/0x14)
[<c0011f74>] (show_stack) from [<c004ed1c>] (do_raw_spin_lock+0x11c/0x13c)
[<c004ed1c>] (do_raw_spin_lock) from [<c02d44c0>] (msm_console_write+0x78/0x188)
[<c02d44c0>] (msm_console_write) from [<c0052880>] (call_console_drivers.constprop.22+0xb4/0x144)
[<c0052880>] (call_console_drivers.constprop.22) from [<c0053570>] (console_unlock+0x27c/0x4ac)
[<c0053570>] (console_unlock) from [<c0053bb4>] (vprintk_emit+0x1f4/0x5a8)
[<c0053bb4>] (vprintk_emit) from [<c04ad0ac>] (printk+0x30/0x40)
[<c04ad0ac>] (printk) from [<c02c2990>] (__handle_sysrq+0x58/0x1b8)
[<c02c2990>] (__handle_sysrq) from [<c02d41b0>] (msm_irq+0x694/0x6f8)
[<c02d41b0>] (msm_irq) from [<c0055740>] (handle_irq_event_percpu+0x58/0x270)
[<c0055740>] (handle_irq_event_percpu) from [<c0055994>] (handle_irq_event+0x3c/0x5c)
[<c0055994>] (handle_irq_event) from [<c0057e84>] (handle_level_irq+0x9c/0x138)
[<c0057e84>] (handle_level_irq) from [<c005509c>] (generic_handle_irq+0x24/0x38)
[<c005509c>] (generic_handle_irq) from [<c000f730>] (handle_IRQ+0x44/0xb0)
[<c000f730>] (handle_IRQ) from [<c0008518>] (msm_vic_handle_irq+0x44/0x64)
[<c0008518>] (msm_vic_handle_irq) from [<c04b5ac4>] (__irq_svc+0x44/0x7c)
Exception stack(0xc0719f68 to 0xc0719fb0)
9f60:                   00000001 00000001 00000000 c0722938 c0718000 c0769acc
9f80: 00000000 c0720098 c0769305 4117b362 c0769acc 00000000 01000000 c0719fb0
9fa0: c004cab0 c000f880 20000013 ffffffff
[<c04b5ac4>] (__irq_svc) from [<c000f880>] (arch_cpu_idle+0x20/0x30)
[<c000f880>] (arch_cpu_idle) from [<c004691c>] (cpu_startup_entry+0xf4/0x23c)
[<c004691c>] (cpu_startup_entry) from [<c06d8b70>] (start_kernel+0x32c/0x394)

Cc: Frank Rowand <frank.rowand@sonymobile.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Enables PPS support in mxs-auart serial driver to make PPS API working.
Signed-off-by: NJanusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Handle CTS/DSR/RI/DCD GPIO interrupts in mxs-auart.
Signed-off-by: NJanusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Dedicated CTS and RTS pins are unusable together with a lot of other
peripherals because they share the same line. Pinctrl is limited.

Moreover, the AUART controller doesn't handle DTR/DSR/DCD/RI signals,
so we have to control them via GPIO.

This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI
signals.
Signed-off-by: NJanusz Uzycki <j.uzycki@elproma.com.pl>
Reviewed-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Russell King:
The only thing which the .get_mctrl method is supposed to do is
to return the state of the /input/ lines, which are CTS, DCD, DSR, RI.
The output line state is stored in port->mctrl, and is added to
the returned value by serial_core when it's required.
RTS output state should not be returned from the .get_mctrl method.

This patch removes ctrl variable from mxs_auart_port
and removes useless reading back RTS line.

The ctrl variable in mxs_auart_port duplicated mctrl,
member of uart_port structure in serial_core.h.
The removed code from mxs_auart_set_mctrl() and mxs_auart_get_mctrl
duplicated uart_update_mctrl() and uart_tiocmget()
in serial_core.c.
Signed-off-by: NJanusz Uzycki <j.uzycki@elproma.com.pl>
Reviewed-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch swaps the use "tail" and "head" to fit the semantic of the linux
circular buffer documentation:
- head: the point at which the producer (the DMA controller) inserts items.
- tail: the point at which the consumer (the serial framework) finds the next
        item.

Besides the former code of the rx ring buffer didn't manage the case where
head < tail, which might lead to loss of data. To fix this bug the data are now
sent from the DMA buffer to the serial framework in two steps:
1 - First, we test if head < tail. If so, we copy the data from tail to the end
    of the DMA buffer then reset tail to zero.
2 - Finally, we copy data from tail to head then set tail to head.

In addition, since tty_insert_flip_string() may now be called twice,
atmel_flip_buffer_rx_dma() becomes less efficient than moving the calls
dma_sync_sg_for_cpu(), dma_sync_sg_for_device(), tty_insert_flip_string() and
tty_flip_buffer_push() directly into atmel_rx_from_dma().
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the config symbol for Mediatek MT7620 SoC to the SERIAL_8250_RT288X
dependencies.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Ralink RT2880 SoC and its successors have an internal 8250 core. This core
needs the same quirks applied as the AMD AU1xxx uart. In addition to these
quirks, the ports memory region is only 0x100 unlike the AU1xxx which has a
size of 0x1000.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Increase the maximum number of consoles possible to 10 since DRA7 now
has the maximum number of consoles possible. without doing this, for
example, enabling DRA7 UART10 results in internal data structures and
console cannot match up and we endup with a crash as follows:

[    1.903503] omap_uart 48424000.serial: [UART-1]: failure [serial_omap_probe]: -22
[    1.911437] omap_uart: probe of 48424000.serial failed with error -22
[    1.920379] Unable to handle kernel NULL pointer dereference at virtual address 00000004
[    1.928894] pgd = c0004000
[    1.931732] [00000004] *pgd=00000000
[    1.935485] Internal error: Oops: 5 [#1] SMP ARM
[    1.940338] Modules linked in:
[    1.943542] CPU: 1 PID: 12 Comm: kworker/1:0 Tainted: G        W      3.18.0-rc1-00001-g8821bc4-dirty #6
[    1.953521] task: ed8a2d00 ti: ed8a4000 task.ti: ed8a4000
[    1.959197] PC is at process_one_work+0x38/0x4a4
[    1.964050] LR is at 0x0
[    1.966705] pc : [<c00548e0>]    lr : [<00000000>]    psr: 40000093
[    1.966705] sp : ed8a5ea8  ip : ed8a5ec8  fp : eeb9abc0
[    1.978759] r10: ed8a4000  r9 : 00000008  r8 : ed842458
[    1.984252] r7 : 00000000  r6 : eeb9abc0  r5 : ed842440  r4 : edbf26a8
[    1.991119] r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : 00000000
[    1.997985] Flags: nZcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[    2.005767] Control: 10c5387d  Table: 8000406a  DAC: 00000015
[    2.011810] Process kworker/1:0 (pid: 12, stack limit = 0xed8a4248)
[    2.018371] Stack: (0xed8a5ea8 to 0xed8a6000)
[    2.022949] 5ea0:                   00000001 00000000 60000093 c008346c 00000001 ed8a5ec8
[    2.031555] 5ec0: c0054de4 eeb9abc0 ed8a4000 ed842458 00000008 ed8a4000 eeb9abc0 ed842440
[    2.040161] 5ee0: eeb9abc0 eeb9abf0 ed8a4000 ed842458 00000008 ed8a4000 eeb9abc0 c0054ec4
[    2.048767] 5f00: ed8a4000 eeb9ac4c a0000053 00000000 ed845bc0 ed842440 c0054d80 00000000
[    2.057342] 5f20: 00000000 00000000 00000000 c005999c 00000001 00000000 c05eaa64 ed842440
[    2.065948] 5f40: 00000000 00000000 dead4ead ffffffff ffffffff c097c680 00000000 00000000
[    2.074554] 5f60: c078acd4 ed8a5f64 ed8a5f64 00000000 00000000 dead4ead ffffffff ffffffff
[    2.083160] 5f80: c097c680 00000000 00000000 c078acd4 ed8a5f90 ed8a5f90 600000d3 ed845bc0
[    2.091766] 5fa0: c00598d4 00000000 00000000 c000e668 00000000 00000000 00000000 00000000
[    2.100341] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    2.108947] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 90005148 11010482
[    2.117553] [<c00548e0>] (process_one_work) from [<c0054ec4>] (worker_thread+0x144/0x498)
[    2.126159] [<c0054ec4>] (worker_thread) from [<c005999c>] (kthread+0xc8/0xe4)
[    2.133758] [<c005999c>] (kthread) from [<c000e668>] (ret_from_fork+0x14/0x2c)
[    2.141357] Code: e1a04001 e1a05000 e893000f e31e0004 (e5978004)
[    2.147766] ---[ end trace 5798e2803311b69f ]---
<snip>

The final solution is to transition off to use 8250 driver and no
dependency on console structures and move away from omap-serial
driver, hence no major cleanups are done for this driver, so add a
simple check to prevent future crashes in a similar manner in case of
platform with additional ports.
Signed-off-by: NNishanth Menon <nm@ti.com>
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 479e9b94 ("serial: Refactor uart_flush_buffer() from
uart_close") refactored the uart_flush_buffer() in uart_close() into
those drivers that define a flush_buffer() method. However, in the
amba-pl011 driver configured without CONFIG_DMA_ENGINE, flush_buffer()
is a NULL method, so the direct call fails to compile.

Check and call the flush_buffer() method through the ops table instead.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes sparse warning:
"obsolete struct initializer, use C99 syntax"
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>