If the serial_core ring buffer empties just as the tty layer receives
an XOFF, then start_tx will never be called when the tty layer
receives an XON as the serial_core ring buffer is empty.  This will
possibly leave a few bytes trapped in the fifo for drivers that
disable the transmitter when flow controlled.
Signed-off-by: NSeth Bollinger <sethb@digi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Wolfram Sang pointed out that "efm32,$device" is non-standard. So use the
common scheme and prefix device with "efm32-". The old compatible string
is left in place until arch/arm/boot/dts/efm32* is fixed.
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NSanjay Singh Rawat <sanjay.rawat@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have
not been used for some time, so remove them to clean up code a bit.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[rjw: Changelog]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Provided that the SER_RS485_RX_DURING_TX flag is not set, empty the
RX FIFO to prevent reading back the transmitted data.
Signed-off-by: NDimitris Lampridis <dlampridis@logikonlabs.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure that serial_omap_stop_rx() also disables RDI (Receiver Data Interrupt),
otherwise the interrupt handler will call serial_omap_rdi() to read the new data,
resulting in the transmission being echoed back.

When the half-duplex transmission is complete, in order to reverse the effects of
serial_omap_stop_rx(), we should re-enable:

  * the RX interrupts _without_ overwriting up->ier

  * the UART_LSR_DR bit of the up->port.read_status_mask
Signed-off-by: NDimitris Lampridis <dlampridis@logikonlabs.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing newlines and coalesce formats.
Realign arguments.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make banner const while we're at it
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When unbinding a serial driver that's being used as a serial console,
the kernel may crash with a NULL pointer dereference in a uart_*() function
called from uart_close () (e.g. uart_flush_buffer() or
uart_chars_in_buffer()).

To fix this, let uart_close() check for port->count == 0. If this is the
case, bail out early. Else tty_port_close_start() will make the port
counts inconsistent, printing out warnings like

    tty_port_close_start: tty->count = 1 port count = 0.

and

    tty_port_close_start: count = -1

and once uport == NULL, it will also crash.

Also fix the related crash in pr_debug() by checking for a non-NULL uport
first.

Detailed description:

On driver unbind, uart_remove_one_port() is called. Basically it;
  - marks the port dead,
  - calls tty_vhangup(),
  - sets state->uart_port = NULL.

What will happen depends on whether the port is just in use by e.g. getty,
or was also opened as a console.

A. If the tty was not opened as a console:

  - tty_vhangup() will (in __tty_hangup()):
      - mark all file descriptors for this tty hung up by pointing them to
	hung_up_tty_fops,
      - call uart_hangup(), which sets port->count to 0.

  - A subsequent uart_open() (this may be through /dev/ttyS*, or through
    /dev/console if this is a serial console) will fail with -ENXIO as the
    port was marked dead,
  - uart_close() after the failed uart_open() will return early, as
    tty_hung_up_p() (called from tty_port_close_start()) will notice it was
    hung up.

B. If the tty was also opened as a console:

  - tty_vhangup() will (in __tty_hangup()):
      - mark non-console file descriptors for this tty hung up by pointing
	them to hung_up_tty_fops,
      - NOT call uart_hangup(), but instead call uart_close() for every
        non-console file descriptor, so port->count will still have a
	non-zero value afterwards.

  - A subsequent uart_open() will fail with -ENXIO as the port was
    marked dead,
  - uart_close() after the failed uart_open() starts to misbehave:
      - tty_hung_up_p() will not notice it was hung up,
      - As port->count is non-zero, tty_port_close_start() will decrease
        port->count, making the tty and port counts inconsistent. Later,
	warnings like these will be printed:

	    tty_port_close_start: tty->count = 1 port count = 0.

	and
	    tty_port_close_start: count = -1

      - If all of this happens after state->uart_port was set to zero, a
        NULL pointer dereference will happen.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Suggested-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds cond_sched() calls during wait loop to perform
other tasks.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

While reviewing an i2c driver for efm32 that needs a similar property
Wolfram Sang pointed out that "location" is a too generic name for something
that is efm32 specific. So add an appropriate namespace and fall back to the
generic name in case of failure.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

cris allmodconfig:

drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
drivers/tty/serial/max310x.c:885:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
drivers/tty/serial/max310x.c:916:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In -RT the spin_lock_irqsave() does not spin but sleep if the lock is
taken. Before that, local_irq_save() is invoked which disables
interrupts even on -RT. Therefore local_irq_save() + spin_lock() does not
work.
In the ->sysrq and oops_in_progress case it is save to trylock the lock
i.e. this is what we do now anyway except for ->sysrq where we assume
that the lock is already taken.

The spin_lock_irqsave() grabs the lock and disables the interrupts on
vanilla (the same behavior) and on -RT it won't disable interrupts.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
[bigeasy: add a patch description]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Intel BayTrail HSUART power-on default reference clock is 44.2368 MHz,
but 73.728 MHz provides 0% error for additional "conventional" baud rates
above 460800 (e.g. 576000, 921600, and 1152000).
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Support the following additional baud rates with 0% error:
	500000, 1500000, 2500000, 3500000
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NAllen Pais <allen.pais@oracle.com>

If cpufreq_register_notifier() fails, we have to remove the port added by
sci_probe_single(), which is not done by sci_cleanup_single().

Else the serial port stays active from the point of view of the serial
subsystem, and it may crash when userspace getty is started, or when the
loadable driver module is unloaded.

This was introduced by commit 6dae1421
("serial: sh-sci: Fix probe error paths").
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the serial port being removed is used as a console, it must also be
unregistered from the console subsystem using unregister_console().

uart_ops.release_port() will release resources (e.g. iounmap() the serial
port registers), causing a crash on subsequent kernel output if the console
is still registered.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 95e629b7 removed the use of board
specific hooks in serial_at91.h, so now, the open/close hook are just
dead code.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For better consistency.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use devm_ioremap_resource() in order to make the code simpler and
it gives proper codes on errors.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a matching table for the the bcm63xx_uart driver on the compatible
string "brcm,bcm6345-uart" which covers all BCM63xx implementations and
reflects the fact that this block was first introduced with the BCM6345
SoC.  Also make sure that we convert the id based on the uart aliases
provided by the relevant Device Tree.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The bcm63xx_uart driver uses RSET_UART_SIZE which is a constant defined
for MIPS-based BCM63xx platforms, pull this constant value from the
MIPS-specific header and put it in include/linux/serial_bcm63xx.h to
make the driver platform agnostic.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Include linux/io.h which provides the definition for
__raw_{readl,writel}, this is not necessary on MIPS since there is an
implicit inclusion, but it is on ARM for instance.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Every couple of months, someone sends a patch to fix:

drivers/tty/serial/8250/8250_core.c: In function 'serial_unlink_irq_chain':
drivers/tty/serial/8250/8250_core.c:1712:2: warning: 'i' may be used uninitialized in this function [-Wuninitialized]

and they in turn get a NACK for their efforts, and are told that
their compiler is broken.  This has been going on since at least
the year 2008:  https://lkml.org/lkml/2008/11/24/433

Lets add a comment, so that subsequent patches don't get as far as
the maintainers or the mailing lists.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add dma support for lpuart. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
Signed-off-by: NYuan Yao <yao.yuan@freescale.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

sparse warnings: (new ones prefixed by >>)

>> drivers/tty/serial/max310x.c:906:45: sparse: incorrect type in argument 2 (different address spaces)
 drivers/tty/serial/max310x.c:906:45: expected void const [noderef] <asn:1>*from
 drivers/tty/serial/max310x.c:906:45: got struct serial_rs485 *<noident>
>> drivers/tty/serial/max310x.c:938:35: sparse: incorrect type in argument 1 (different address spaces)
 drivers/tty/serial/max310x.c:938:35: expected void [noderef] <asn:1>*to
 drivers/tty/serial/max310x.c:938:35: got struct serial_rs485 *<noident>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig symbol SVINTO_SIM got dropped in commit e269a869 ("Drop
code for CRISv10 CPU simulator"). Now drop the remaining code for that
simulator.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This is a temporary solution to fix following issue:
config: make ARCH=alpha allyesconfig

All error/warnings:

 drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
>> drivers/tty/serial/max310x.c:905:7: error: 'TIOCSRS485' undeclared (first use in this function)
 drivers/tty/serial/max310x.c:905:7: note: each undeclared identifier is reported only once for each function it appears in
>> drivers/tty/serial/max310x.c:906:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
>> drivers/tty/serial/max310x.c:929:7: error: 'TIOCGRS485' undeclared (first use in this function)
>> drivers/tty/serial/max310x.c:938:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
 cc1: some warnings being treated as errors
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit e3c6ea9b as it
didn't help anything, and caused more problems than expected.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

instead of using sirf specific dma channel property like "sirf,uart-dma-rx-channel"
and "sirf,uart-dma-tx-channel", here we move to use generic dma dt-binding to get
the channel like:
- sirf,uart-dma-rx-channel = <21>;
- sirf,uart-dma-tx-channel = <2>;
+ dmas = <&dmac1 5>, <&dmac0 2>;
+ dma-names = "rx", "tx";

and we move dma_request_channel() to dma_request_slave_channel(), we don't need to
call sirfsoc dma filter function sirfsoc_dma_filter_id() again.
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically happen
during device probe call.

In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with same default major/minor numbers are
included in the kernel.

A typical case is observed with amba-pl011 and samsung-uart drivers.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>