This patch fixes a below warning reported by kbuild test robot.
drivers/tty/serial/st-asc.c:727:28: warning: 'asc_match' defined but
not used [-Wunused-variable]
The code used in DT case is now ifdefed under CONFIG_OF to fix this
warning.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Reported-by: Kbuild Test Robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 85c9969074.
Alexander wishes to remove this patch as it is incorrect.
Reported-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, Rx error handling only triggers if there is some Rx data.
Fix that by checking for error - before the data handling.
Reported-by: Mischa Jonker <mjonker@synopsys.com>
Tested-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instrumented testing shows a tty can be hungup multiple times [1].
Although concurrent hangups are properly serialized, multiple
hangups for the same tty should be prevented.
If tty has already been HUPPED, abort hangup. Note it is not
necessary to cleanup file *redirect on subsequent hangups,
as only TIOCCONS can set that value and ioctls are disabled
after hangup.
[1]
Test performed by simulating a concurrent async hangup via
tty_hangup() with a sync hangup via tty_vhangup(), while
__tty_hangup() was instrumented with:
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 26bb78c..fe8b061 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -629,6 +629,8 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
tty_lock(tty);
+ WARN_ON(test_bit(TTY_HUPPED, &tty->flags));
+
/* some functions below drop BTM, so we need this bit */
set_bit(TTY_HUPPING, &tty->flags);
Test result:
WARNING: at /home/peter/src/kernels/mainline/drivers/tty/tty_io.c:632 __tty_hangup+0x459/0x460()
Modules linked in: ip6table_filter ip6_tables ebtable_nat <...snip...>
CPU: 6 PID: 1197 Comm: kworker/6:2 Not tainted 3.10.0-0+rfcomm-xeon #0+rfcomm
Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012
Workqueue: events do_tty_hangup
0000000000000009 ffff8802b16d7d18 ffffffff816b553e ffff8802b16d7d58
ffffffff810407e0 ffff880254f95c00 ffff880254f95c00 ffff8802bfd92b00
ffff8802bfd96b00 ffff880254f95e40 0000000000000180 ffff8802b16d7d68
Call Trace:
[<ffffffff816b553e>] dump_stack+0x19/0x1b
[<ffffffff810407e0>] warn_slowpath_common+0x70/0xa0
[<ffffffff8104082a>] warn_slowpath_null+0x1a/0x20
[<ffffffff813fb279>] __tty_hangup+0x459/0x460
[<ffffffff8107409c>] ? finish_task_switch+0xbc/0xe0
[<ffffffff813fb297>] do_tty_hangup+0x17/0x20
[<ffffffff8105fd6f>] process_one_work+0x16f/0x450
[<ffffffff8106007c>] process_scheduled_works+0x2c/0x40
[<ffffffff8106060a>] worker_thread+0x26a/0x380
[<ffffffff810603a0>] ? rescuer_thread+0x310/0x310
[<ffffffff810698a0>] kthread+0xc0/0xd0
[<ffffffff816b0000>] ? destroy_compound_page+0x65/0x92
[<ffffffff810697e0>] ? kthread_create_on_node+0x130/0x130
[<ffffffff816c495c>] ret_from_fork+0x7c/0xb0
[<ffffffff810697e0>] ? kthread_create_on_node+0x130/0x130
---[ end trace 98d9f01536cf411e ]---
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add DT support to the SCCNCP serial driver.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces switch in probe function to constant structure
for each supported IC. This makes code a bit smaller and cleaner and
helps adding DT support to the driver in the future.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes "frequency" parameter from SCCNXP platform_data
and uses CLK API for getting clock. If CLK ommited, default IC
frequency will be used instead.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The patch disables the regulator in case of errors, if we have it.
In addition, the patch adds support for deferred regulator probe and
makes error path are a bit clean.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pdev->id is not a valid choice for device-tree probed devices. So use
the (properly determined) line from efm32_uart_probe consistenly
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can't use dev->mod_index for selecting the interrupt routing entry,
because it's not an index into interrupt routing table. It will be even
wrong on a machine with 2 CPUs (4 cores). But all needed information is
contained in the PAT entries for the serial ports. mod[0] contains the
iosapic address and mod_info has some indications for the interrupt
input (at least it looks like it). This patch implements the searching
for the right iosapic and uses this interrupt input information.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: <stable@vger.kernel.org> # 3.10
Signed-off-by: Helge Deller <deller@gmx.de>
Storing one struct per known board would be overkill. Pre-cast the
driver_data pointer to an unsigned long to avoid the pointer to int
compiler warning:
drivers/tty/serial/pch_uart.c:431:10: warning: cast from pointer to
integer of different size [-Wpointer-to-int-cast]
Unify the signed-ness of the baud and uartclk types throughout the
driver.
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because the UART lack of receive timeout register, so we use a timer to trigger
data receive.
The DBGU is regarded as UART.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Distinguish usart and uart by read ip name register,
The usart read name is "USAR",
The uart and dbgu read name is "DBGU".
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will switch to pio mode when request of dma or pdc fail.
But soon or later, when the request is success, the transfer mode can switch to them at
next open serial port action.
So in startup stage, we should get original transfer mode.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Request a cyclic dma channel for rx dma use. Use cyclic transfer is to prevent
receive data overrun.
We allocate a cycle dma cookie after request channel,
after that, enable uart timeout interrupt in startup stage, when data successful
received, the timeout callback will check the residual bytes and insert
receiving datas into the framework during the transfer interval.
When current descriptor finished, the dma callback will also check the residual
bytes and filp the receiving data.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Request a slave dma channel for tx dma use. Tx dma will setup a single transfer,
when transfer complete, it will call atmel_complete_tx_dma to do finish stuff.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
use function pointer can avoid define atmel_use_pdc_tx/rx everywhere.
(*prepare_rx/tx)() is in setup transfer stage.
(*schedule_rx/tx)() is in tasklet schedule stage.
(*release_rx/tx)() is used when shutdown the transfer.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DMA is available since at91sam9x5 socs, before that, we use PDC.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dmi_table is best accessed from the probe function, which is not
an __init function. Drop the __initdata annotation from the dmi_table
to avoid the section mismatch compiler warnings:
WARNING: drivers/tty/serial/pch_uart.o(.text+0x4871): Section mismatch
in reference from the function pch_uart_init_port() to the variable
.init.data:pch_uart_dmi_table
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Found with coccinelle, manually fixed and verified.
Signed-off-by: Alexandru Juncu <alexj@rosedu.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes wrong dev_pm_ops which caused by commit:
serial: max310x: Driver rework.
CC drivers/tty/serial/max310x.o
LD drivers/video/fb.o
CC drivers/w1/slaves/w1_ds2433.o
CC drivers/w1/slaves/w1_ds2760.o
CC drivers/xen/balloon.o
CC drivers/video/backlight/adp8870_bl.o
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.suspend') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.resume') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.freeze') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.thaw') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.poweroff') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.restore') [enabled by default]
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Platform drivers use "platform:" prefix in module alias.
Also use DRIVER_NAME in MODULE_ALIAS to make module autoloading work.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function tty_port_tty_hangup() could leak a reference to the tty_struct:
struct tty_struct *tty = tty_port_tty_get(port);
if (tty && (!check_clocal || !C_CLOCAL(tty))) {
tty_hangup(tty);
tty_kref_put(tty);
}
If tty != NULL and the second condition is false we never call tty_kref_put and
the reference is leaked.
Fix by always calling tty_kref_put() which accepts a NULL argument.
The patch fixes a regression introduced by commit aa27a094.
Acked-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org> # 3.10
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without this patch the driver waits ~1 ms for the UART to become idle. At
115200n8 this time is (theoretically) enough to transfer 11.5 characters
(= 115200 bits/s / (10 Bits/char) * 1ms). As the mxs-auart has a fifo size
of 16 characters the clock is gated too early. The problem is worse for
lower baud rates.
This only happens to really shut down the transmitter in the middle of a
transfer if /dev/ttyAPPx isn't opened in userspace (e.g. by a getty) but
was at least once (because the bootloader doesn't disable the transmitter).
So increase the timeout to 20 ms which should be enough for 9600n8, too.
Moreover skip gating the clock if the timeout is elapsed.
Cc: stable@vger.kernel.org # v2.6.39+
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The handler needs to ack the pending events before actually handling them.
Otherwise a new event might come in after it it considered non-pending or
handled and is acked then without being handled. So this event is only
noticed when the next interrupt happens.
Without this patch an i.MX28 based machine running an rt-patched kernel
regularly hangs during boot.
Cc: stable@vger.kernel.org # v2.6.39+
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace kzalloc and clk_get by their managed counterparts to simplify
error and cleanup paths.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-> The ledptrs[] array is never initialized.
-> There is no place where kbd->ledmode is set to LED_SHOW_MEM therefore the if
statement does not make much sense.
-> Since LED_SHOW_MEM is not used, it can be removed from the header file as well.
Signed-off-by: Andreas Platschek <andi.platschek@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UARTDM cores have a TX fifo that can accept more than one
character per register write, but the msm_serial driver currently
only supports 1 character mode. Add support for this mode of operation
to speed up the transmit path on DM devices.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently msm_set_baud_rate() assumes the uart clock rate is
1.8432 MHz. This is not always true, and limits our options to
program the baud rate. Instead of assuming the rate and
hard-coding the baud_code based on it, calculate the divider that
we want and try to find the closest baud_code that matches. This
allows us to support uarts with faster clock speeds.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/msm_serial.c:302:6: warning: symbol 'msm_set_mctrl' was
not declared. Should it be static?
drivers/tty/serial/msm_serial.c:597:17: warning: incorrect type in argument 2
(different address spaces)
drivers/tty/serial/msm_serial.c:597:17: expected void volatile [noderef] <asn:2>*addr
drivers/tty/serial/msm_serial.c:597:17: got unsigned int *
drivers/tty/serial/msm_serial.c:608:33: warning: incorrect type in argument 1
(different address spaces)
drivers/tty/serial/msm_serial.c:608:33: expected void volatile [noderef] <asn:2>*addr
drivers/tty/serial/msm_serial.c:608:33: got unsigned int *gsbi_base
drivers/tty/serial/msm_serial.c:648:37: warning: incorrect type in assignment
(different address spaces)
drivers/tty/serial/msm_serial.c:648:37: expected unsigned int *gsbi_base
drivers/tty/serial/msm_serial.c:648:37: got void [noderef] <asn:2>*
Mark the ioremapped memory as __iomem and use writel instead of
iowrite because we're not dealing with PCI devices. Also, mark
msm_set_mctrl() static because it isn't used outside this file.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UARTDM serial devices require us to wait for the entire TX fifo
to drain before we can change the contents of the NCF_TX
register. Furthermore, if we write any characters to the TX fifo
within the same clock cycle of changing the NCF_TX register the
NCF_TX register won't latch properly.
To fix these issues we should read back the NCF_TX register to
delay any TX fifo accesses by a clock cycle and we should wait
for the TX fifo to drain (instead of just waiting for the fifo to
be ready to receive more characters). Failure to do so leads to
random NUL bytes interspersed in the output.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The quirks and PCI ID table entries for the original ADDI-DATA APCI-7800
(not the newer APCI-7800-3) use PCI_DEVICE_ID_ADDIDATA_APCI7800 from
<linux/pci_ids.h> but the device ID was actually assigned to ADDI-DATA
by Applied Micro Circuits Corporation (PCI_VENDOR_ID_AMCC). Replace it
locally with #define PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI_VENDOR_ID_ADDIDATA_OLD has the same value (0x10e8) as
PCI_VENDOR_ID_AMCC in <linux/pci_ids.h>. The vender ID is actually
assigned to Applied Micro Circuits Corporation. The 8250_pci driver
uses PCI_VENDOR_ID_ADDIDATA_OLD in the lists of quirks and PCI IDs for
the ADDI-DATA APCI-7800 card. Change it to use the more accurate
PCI_VENDOR_ID_AMCC.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support to ASC (asynchronous serial controller)
driver, which is basically a standard serial driver. This IP is common
across all the ST parts for settop box platforms.
ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
It support all industry standard baud rates.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Stephen Gallimore <stephen.gallimore@st.com>
CC: Stuart Menefy <stuart.menefy@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver fails to build on x86 because writel_relaxed isn't available
there. That function exists on arm, arm64, avr32, hexagon, mips and sh,
but adding all these is overkill so stick to arm only.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the missing iounmap() before return from msm_request_port()
in the error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No idea why we have redundant testing for ifdef CONFIG_SERIAL_BFIN_MODULE,
check it once is enough.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the DMI interface rather than manually matching DMI strings.
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: Michael Brunner <mibru@gmx.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some serial ports will not use the standard base baud rate. Report
this after initialization so it might be discovered and used for early
console configuration.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If earlyprintk is enabled and current UART is console port the platform
code can mark it as RPM_ACTIVE to sync real IP state with PM Runtime and
avoid resuming of already active device, but now, driver initialization
will be performed in the wrong way:
pm_runtime_enable(&pdev->dev);
<-- PM runtime alowed (device state RPM_ACTIVE)
if (omap_up_info->autosuspend_timeout == 0)
omap_up_info->autosuspend_timeout = -1;
device_init_wakeup(up->dev, true);
pm_runtime_use_autosuspend(&pdev->dev);
<-- update_autosuspend() will be called and it will disable device
(device state RPM_SUSPENDED)
pm_runtime_set_autosuspend_delay(&pdev->dev,
omap_up_info->autosuspend_timeout);
<-- update_autosuspend() will be called which will re-enable device
(device state RPM_ACTIVE), because autosuspend_timeout < 0
pm_runtime_irq_safe(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
<-- will do nothing
Such behavior isn't expected by OMAP serial drivers and causes
unpredictable calls of serial_omap_runtime_suspend() and
serial_omap_runtime_resume().
Hence, fix it by allowing PM runtime only after all its parameters are
configured.
CC: Tony Lindgren <tony@atomide.com>
CC: Rajendra Nayak <rnayak@ti.com>
CC: Felipe Balbi <balbi@ti.com>
CC: Kevin Hilman <khilman@linaro.org>
Tested-by: Mark Jackson <mpfj-list@newflow.co.uk>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Function lpuart_setup_watermark() clears some bits in register UARTCR2
before writing FIFO configuration registers as required by hardware.
But it should restore UARTCR2 after that. Otherwise, we end up changing
UARTCR2 register when setting up watermark, and that is not really
desirable. At least, when low-level debug and earlyprint is enabled,
serial console is broken due to it.
Fix the problem by restoring UARTCR2 register at the end of function
lpuart_setup_watermark().
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
