Fix panic caused by a race between men_z135_intr() and men_z135_set_termios().
men_z135_intr() and men_z135_set_termios() both hold the struct uart_port::lock
spinlock, but men_z135_intr() does a spin_lock_irqsave() and
men_z135_set_termios() does a normal spin_lock(), which can lead to a deadlock
when an interrupt is called while the lock is being helt by
men_z135_set_termios().
This was discovered using a insmod, hardware looppback send/receive, rmmod
stress test.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: Andreas Werner <andreas.werner@men.de>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SMSC IrCC SIR/FIR port should not be bound to by
(legacy) serial driver so its own driver (smsc-ircc2)
can bind to it.
Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently mxs-auart doesn't care correctly about the baud rate divisor.
According to reference manual the baud rate divisor must be between
0x000000EC and 0x003FFFC0. So calculate the possible baud rate range
and use it for uart_get_baud_rate().
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Whenever the UART device driver gets closed from userland, the driver
disables the UART unit and then stops the clocks to save power.
The bit which disabled the UART unit is described as:
"UART Enable. If this bit is set to 1, the UART is enabled. Data
transmission and reception occurs for the UART signals. When the
UART is disabled in the middle of transmission or reception, it
completes the current character before stopping."
The important part is the "it completes the current character". Whenever
a reception is ongoing when the UART gets disabled (including the clock
off) the statemachine freezes and "remembers" this state on the next
open() when re-enabling the unit's clock.
In this case we end up receiving an additional bogus character
immediately.
The solution in this change is to switch the AUART unit into its reset
state on close() and only release it from its reset state on the next
open().
Note: when the unit is also used as system console it is always 'in use',
so we cannot reset it on close().
Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This function clears the reset the AUART unit is in after system start
to make it work.
Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix RS232/485 mode incorrect setting after S3/S4 resume for F81504/508/512
We had add RS232/485 RTS control with fecf27a373. But when it
resume from S3/S4, the mode register 0x40 + 0x08 * idx + 7 will
rewrite to 0x01 (RS232 mode).
This patch will modify 2 sections.
One is pci_fintek_init(), if it called when first init, it will
write mode register with 0x01. If it called from S3/S4 resume,
it's will get the relative port data and pass it to
pci_fintek_rs485_config() with NULL rs485 parameter.
The another modification is in pci_fintek_rs485_config(). It'll
re-apply old configuration when the parameter rs485 is NULL.
Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
devtype structures are all declared as const.
Compiler does not complain because we cast
their pointers to save them in .driver_data.
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We currently register the uart driver during device probe
which makes it hard to support more than one chip.
Move the driver registration to module init/exit time and
preallocate space for up to 8 lines (4-8 chips).
Reported-by: Michael Allwright <michael.allwright@upb.de>
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation of supporting multiple devices we should save
the per-chip line number (0 or 1), because the uart_port line
will reflect system-wide uart number and will be offseted for
chips other than the first to register.
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Support ZTE uart with some registers differing offset.
Probe as platform device for not AMBA IP ID is
available on ZTE uart.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Improve LCRH register access decision as ARM PL011 lcrh
register serve as both TX and RX, while other SOC may
implement TX and RX function with separated register.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce register look up table as different SOC venders
may have different register offset for the some register.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce register accessor to ease loop up table access
in later patch.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rename regs with enumeration to generalize register names.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pericom PI7C9X795[1248] are Uno/Dual/Quad/Octal UART devices, this
patch enables them, also defines PCI_VENDOR_ID_PERICOM here.
Signed-off-by: Adam Lee <adam.lee@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So far DMA mode were activated when only number of bytes to send was
equal or greater than min_dma_size. Due to requirement that DMA transaction
buffer should be aligned to cache line size, the excessive bytes were
written to FIFO before starting DMA transaction. The problem occurred
when FIFO size were smaller than cache alignment, because writing all
excessive bytes to FIFO would fail. It happened in DMA mode when PIO
interrupts disabled, which caused driver hung.
The solution is to test if buffer is alligned to cache line size before
activating DMA mode, and if it's not, running PIO mode to align buffer
and then starting DMA transaction. In PIO mode, when interrupts are
enabled, lack of space in FIFO isn't the problem, so buffer aligning
will always finish with success.
Cc: <stable@vger.kernel.org> # v3.18+
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to some of serial ports can have FIFO size smaller than cache line
size, and because of need to align DMA buffer address to cache line size,
it's necessary to calculate minimum number of bytes for which we want
to start DMA transaction to be at least cache line size. The simplest
way to meet this requirement is to get maximum of cache line size and
FIFO size.
Cc: <stable@vger.kernel.org> # v3.18+
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial core does not use tty_port_open() or tty_port_close(); serial
core defines and extends it's own tty open() and close() methods
(uart_open() and uart_close(), respectively).
Remove the tty_port activate() and shutdown() initializations, and
the uart_port_activate() function, which is never called.
NB: uart_port_shutdown() is used by uart_close() => uart_shutdown()
call chain (but not via the tty_port methods).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_close() runs in non-atomic context only; use
spin_lock/unlock_irq instead of saving the interrupt state (which
== on).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes I/O accesses on the Receiver Holding Register and on the
Transmitter Holding Register. Indeed AVR32 can only perform 32bit I/O
accesses on registers: using 8bit I/O accesses would read or write garbage
data.
Fixes: commit b5199d4681 ("tty/serial: at91: add support to FIFOs")
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.
Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to DesignWare 8250 spec, if auto flow control
mode is enabled, a change in CTS does not cause an interrupt,
so sw-assisted CTS flow control mode will not work properly.
There reported an GPS firmware download failure issue, and we
verified the root cause is, the default sw-assisted CTS flow
control mode can not work properly since no interrupt when got
CTS signal.
This patch is to enable auto CTS mode by defaut if CRTSCTS
is enable for DesignWare 8250 controller.
Signed-off-by: Huiquan Zhong <huiquan.zhong@intel.com>
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documenation/serial/driver requests that the tx_empty callback should
return 0 if there are still chars in the fifo or shifter or TIOCSER_TEMT
(0x01) if no character is pending to be sent.
Fix the mpc52xx serial driver to not return MPC52xx_PSC_SR_TXEMP (i.e.
0x0800) but TIOCSER_TEMT as documented.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to use the mctrl_gpio helpers, we change the DT bindings:
ri-gpios renamed to rng-gpios. cd-gpios renamed to dcd-gpios.
However, no in-tree dts/dtsi specifies these, so no worries.
Signed-off-by: Niklas Cassel <nks@flawful.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Implementing enable_ms is optional by serial_core.
check_modem_status is just an empty local function.
Signed-off-by: Niklas Cassel <nks@flawful.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When system goes into low power states like SUSPEND_MEM and
HIBERNATION, the hardware IP block may be powered off to reduce
the power consumption. This power down may cause problems on
some imx platforms, because the hardware settings are reset to
its power on default values which may differ from the ones when
it power off. This patch added the dev_pm_ops and implemented
two callbacks: suspend_noirq and resume_noirq, which will save
the necessory hardware parameters right before power down and
recover them before system uses the hardware.
Because added the dev_pm_ops, the old suspend/resume callbacks
under platform_driver will not be called any more. Changed their
prototypes and moved those two callbacks into dev_pm_ops too.
Signed-off-by: Shenwei Wang <shenwei.wang@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add RS485 control for Fintek F81504/508/512
F81504/508/512 can control their RTS with H/W mode.
PCI configuration space for each port is 0x40 + idx * 8 + 7.
When it set with 0x01, it's configured with RS232 mode.
RTS is controlled by MCR.
When it set with 0x11, it's configured with RS485 mode.
RTS is controlled by H/W, RTS low with idle & RX, high with TX.
When it set with 0x31, it's configured with RS485 mode.
RTS is controlled by H/W, RTS high with idle & RX, low with TX.
We will force 0x01 on pci_fintek_setup().
Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e95044ba4f.
Commit e95044ba4f ("tty: serial: imx.c: Reset UART before activating
interrupts") terribly messes up with the console on mx6 boards, so
let's revert it.
Reported-by: kernelci.org bot <bot@kernelci.org>
Cc: David Jander <david@protonic.nl>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Other serial driver work wants to build on patches now in 4.2-rc4 so
merge the branch so this can properly happen.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Opens of /dev/ptmx don't use tty_open() so debug messages are
not printed for those opens; print a debug message with the
open count (which must always be 1) if TTY_DEBUG_HANGUP is defined.
NB: Each tty core source file undefs support for debug messages.
The relevant source file must be patched/edited to enable these
messages.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add debug messages for ldisc open and close, and remove
"closing ldisc" message from tty_ldisc_release(), because a
close message is now printed for both ldiscs; always print ldisc
pointer first so ldisc changes are easier to identify.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce tty_debug() macro to output uniform debug information for
tty core debug messages (function name and tty name).
Note: printk(KERN_DEBUG) is retained here over pr_debug() since
messages can be enabled in non-DEBUG builds.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Output the function name, tty name, and invariant failure (if applicable).
Add the tty count to the tty_open() message. Fix the disassociate_ctty()
message, which printed the NULL pointer and the wrong message.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Kconfig for this driver is currently:
config SERIAL_SUNHV
bool "Sun4v Hypervisor Console support"
...meaning that it currently is not being built as a module by
anyone. Lets remove the modular and unused code here, so that
when reading the driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
We don't swap module.h for init.h since this file has init.h already.
We leave some tags like MODULE_LICENSE for documentation purposes, and
for the "git blame" value. Also note that MODULE_DEVICE_TABLE is a
no-op for non-modular code, so we remove that too.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: sparclinux@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Kconfig for this driver is currently:
config SERIAL_SUNCORE
bool
...meaning that it currently is not being built as a module by
anyone. Lets remove the modular and unused code here, so that
when reading the driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
We don't swap module.h for init.h since this file has init.h already.
We leave some tags like MODULE_LICENSE for documentation purposes, and
for the "git blame" value.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: sparclinux@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Kconfig for this option is currently:
config SERIAL_LANTIQ
bool "Lantiq serial driver"
...meaning that it currently is not being built as a module by anyone.
Lets remove the couple traces of modularity, so that when reading the
driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
We delete the MODULE_DESCRIPTION and LICENSE tags since they are
not adding any new information above and beyond what is at the top
of the file. Also note that MODULE_DEVICE_TABLE is a no-op for
non-modular code, so we remove that as well.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Kconfig for this option is currently:
config SERIAL_SGI_L1_CONSOLE
bool "SGI Altix L1 serial console support"
...meaning that it currently is not being built as a module by anyone.
Lets remove the orphaned module code, so that when reading the
driver there is no doubt it is builtin-only. We could consider
making it tristate, but the above bool has been there since before
the start of git history, which isn't all that surprising, since
consoles are typically critical to have at early boot. So adding
tristate is really of no value here.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 84f57d9e36 ("tty: serial/samsung: fix modular build") fixed
build issues when the driver was built as a module. One of those was
that printascii is only accessible when the driver is built-in.
But there is no need to check for defined(CONFIG_DEBUG_LL) since the
SERIAL_SAMSUNG_DEBUG Kconfig symbol already depends on DEBUG_LL.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Kukjin Kim <kgene@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The advance of the 'read' buffer index belongs in the outer
flip buffer consume loop, with the other buffer index arithmetic.
No functional change.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clarify flip buffer producer/consumer operation; the use of
smp_load_acquire() and smp_store_release() more clearly indicates
which memory access requires a barrier.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While closing, new rx data may be received after the input buffers
have been flushed but before stop_rx() halts receiving [1]. The
new data might not be processed by flush_to_ldisc() until after
uart_shutdown() and normal input processing is re-enabled (ie.,
tty->closing = 0). The race is outlined below:
CPU 0 | CPU 1
|
uart_close() |
tty_port_close_start() |
tty->closing = 1 |
tty_ldisc_flush() |
| => IRQ
| while (LSR & data ready)
| uart_insert_char()
| tty_flip_buffer_push()
| <= EOI
stop_rx() | .
uart_shutdown() | .
free xmit.buf | .
tty_port_tty_set(NULL) | .
tty->closing = 0 | .
| flush_to_ldisc()
| n_tty_receive_buf_common()
| __receive_buf()
| ...
| commit_echoes()
| uart_flush_chars()
| __uart_start()
| ** OOPS on port.tty deref **
tty_ldisc_flush() |
Input processing must be prevented from echoing (tty->closing = 1)
until _after_ the input buffers have been flushed again at the end
of uart_close().
[1] In fact, some input may actually be buffered _after_ stop_rx()
since the rx interrupt may have already triggered but not yet been
handled when stop_rx() disables rx interrupts.
Fixes: 2e75891083 ("serial: core: Flush ldisc after dropping port
mutex in uart_close()")
Reported-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The maximum bitrate supported depends on the clock rate used in BRG.
This is stored in port.uartclk during probe. Respecting the 16x
oversampling higher bitrates can be supported.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
