Add selective auto-flow-control support for UniPhier serial driver.
Signed-off-by: Dai Okamura <okamura.dai@socionext.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the DT-related settings are split out to
uniphier_of_serial_setup(), but it turned out to be not nice.
The next commit will add a DT property, but it will not fit in
the helper. Merge the helper into the probe function.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The FIFO size of the UART devices is 64 on almost all UniPhier SoCs
with the exception Pro4TV SoC (MN2WS0235), which used 128 FIFO size.
However, Pro4TV SoC was never upstreamed, and out of production.
So, this property has never been used in a useful way.
Let's remove old unused code.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 8250 FIFOs indeed need to be cleared after stopping transmission in
RS485 mode without SER_RS485_RX_DURING_TX flag set. But there are two
problems with the approach taken by the previous patch from Fixes tag.
First, serial8250_clear_fifos() should clear fifos, but what it really
does is it enables the FIFOs unconditionally if present, clears them
and then sets the FCR register to zero, which effectively disables the
FIFOs. In case the FIFO is disabled, enabling it and clearing it makes
no sense and in fact can trigger misbehavior of the 8250 core. Moreover,
the FCR register may contain other FIFO configuration bits which may not
be writable unconditionally and writing them incorrectly can trigger
misbehavior of the 8250 core too. (ie. AM335x UART swallows the first
byte and retransmits the last byte twice because of this FCR write).
Second, serial8250_clear_and_reinit_fifos() completely reloads the FCR,
but what really has to happen at the end of the RS485 transmission is
clearing of the FIFOs and nothing else.
This patch repairs serial8250_clear_fifos() so that it really only
clears the FIFOs by operating on FCR[2:1] bits and leaves all the
other bits alone. It also undoes serial8250_clear_and_reinit_fifos()
from __do_stop_tx_rs485() as serial8250_clear_fifos() is sufficient.
Signed-off-by: Marek Vasut <marex@denx.de>
Fixes: 2bed8a8e70 ("Clearing FIFOs in RS485 emulation mode causes subsequent transmits to break")
Cc: Daniel Jedrychowski <avistel@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org> # let it bake a bit before merging
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit c58caaab3b ("serial: 8250: of: Defer probe on missing IRQ"), a
check was added for the UART driver being probed prior to the parent IRQ
controller.
Unfortunately this breaks certain boards which have no interrupt support,
like Huawei D03.
Indeed, the 8250 DT bindings state that interrupts should be supported -
not must.
To fix, switch from irq_of_parse_and_map() to of_irq_get(), which
does relay whether the IRQ host controller domain is not ready, i.e.
defer probe, instead of assuming it.
Fixes: c58caaab3b ("serial: 8250: of: Defer probe on missing IRQ")
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow 8250 omap serial driver to be used for K3 platforms.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The printk() in serial8250_interrupt() was once hidden behind a debug
macro in commit f4f653e987 ("serial: 8250, disable "too much work"
messages") and reverted back in commit 12de375ec4 ("Revert "serial:
8250, disable "too much work" messages"").
This was introduced first in 0.99.13k with the "serial" driver itself
(and called pass_number with a limit of 64 and no print). In 1.1.13 it
was renamed to pass_counter and the printk was behind #if 0. In 1.1.94
the limit of 64 was increased to 256 and hidden behind
RS_ISR_PASS_LIMIT. With this change the #if 0 turned into #if 1. It
slowly become what we have today with a loop limit of 512.
Usually, that printk isn't hit. However on KVM with a busy UART and
overloaded host it might happen. It is also likely with threaded
interrupts and a task which preempts the interrupt handler.
If the UART has (legitimate) work to do and we break out of the loop,
nothing changes: the interrupt is most likely already pending in the
interrupt controller and we end up in the handler anyway. This printk is
hardly helping.
Older kernels also had a comment saying that a bad configuration might
lead to this but I don't see how that should happen because a wrongly
configured interrupt number would let the handler leave "early" with
IRQ_NONE and the spurious detected will handle that (weill since 2.6.11,
before that we had no spurious detector). In that case, we would never
loop that often here.
This loop looks like an optimisation in order to pull the bytes from the
FIFO which were received while we were already here instead of waiting
for the interrupt. This might have been a good idea while the CPUs were
slow and FIFOs small.
There are other serial driver in tree, like the amba-pl*, which also
have this kind of a loop but without the printk (and were based on this
driver).
Remove the printk which might trigger in otherwise valid situtations.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the bit set of char/misc drivers for 4.19-rc1
There is a lot here, much more than normal, seems like everyone is
writing new driver subsystems these days... Anyway, major things here
are:
- new FSI driver subsystem, yet-another-powerpc low-level
hardware bus
- gnss, finally an in-kernel GPS subsystem to try to tame all of
the crazy out-of-tree drivers that have been floating around
for years, combined with some really hacky userspace
implementations. This is only for GNSS receivers, but you
have to start somewhere, and this is great to see.
Other than that, there are new slimbus drivers, new coresight drivers,
new fpga drivers, and loads of DT bindings for all of these and existing
drivers.
Full details of everything is in the shortlog.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the bit set of char/misc drivers for 4.19-rc1
There is a lot here, much more than normal, seems like everyone is
writing new driver subsystems these days... Anyway, major things here
are:
- new FSI driver subsystem, yet-another-powerpc low-level hardware
bus
- gnss, finally an in-kernel GPS subsystem to try to tame all of the
crazy out-of-tree drivers that have been floating around for years,
combined with some really hacky userspace implementations. This is
only for GNSS receivers, but you have to start somewhere, and this
is great to see.
Other than that, there are new slimbus drivers, new coresight drivers,
new fpga drivers, and loads of DT bindings for all of these and
existing drivers.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
android: binder: Rate-limit debug and userspace triggered err msgs
fsi: sbefifo: Bump max command length
fsi: scom: Fix NULL dereference
misc: mic: SCIF Fix scif_get_new_port() error handling
misc: cxl: changed asterisk position
genwqe: card_base: Use true and false for boolean values
misc: eeprom: assignment outside the if statement
uio: potential double frees if __uio_register_device() fails
eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency
misc: ti-st: Fix memory leak in the error path of probe()
android: binder: Show extra_buffers_size in trace
firmware: vpd: Fix section enabled flag on vpd_section_destroy
platform: goldfish: Retire pdev_bus
goldfish: Use dedicated macros instead of manual bit shifting
goldfish: Add missing includes to goldfish.h
mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux
dt-bindings: mux: add adi,adgs1408
Drivers: hv: vmbus: Cleanup synic memory free path
Drivers: hv: vmbus: Remove use of slow_virt_to_phys()
Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()
...
Revert commit ecb988a3b7: tty: serial:
8250: 8250_core: NXP SC16C2552 workaround
The above commit causes userland application to no longer write
correctly its first write to a dumb terminal connected to /dev/ttyS0.
This commit seems to be the culprit. It's as though the TX FIFO is being
reset during that write. What should be displayed is:
PSW 80000000 INST 00000000 HALT
//
What is displayed is some variation of:
T 00000000 HAL//
Reverting this commit via this patch fixes my problem.
Signed-off-by: Mark Hounschell <dmarkh@cfl.rr.com>
Fixes: ecb988a3b7 ("tty: serial: 8250: 8250_core: NXP SC16C2552 workaround")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sleep wake-up refactoring that I introduced in
commit c7e1b40590 ("tty: serial: exar: Relocate sleep wake-up handling")
did not account for devices with a slave device on the expansion port.
This patch pokes the INT0 register in the slave device, if present, in
order to ensure that MSI interrupts don't get permanently "stuck"
because of a sleep wake-up interrupt as described here:
commit 2c0ac5b48a ("serial: exar: Fix stuck MSIs")
This also converts an ioread8() to readb() in order to provide visual
consistency with the MMIO-only accessors used elsewhere in the driver.
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Fixes: c7e1b40590 ("tty: serial: exar: Relocate sleep wake-up handling")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add ACPI identifier HID for UART DW 8250 on Broadcom SoCs
to match the HID passed through ACPI tables to enable
UART controller.
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Tested-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is
NULL. This happens during resume.
Call Trace:
...
[ 54.928108] dw8250_set_termios+0x162/0x170
[ 54.928114] serial8250_set_termios+0x17/0x20
[ 54.928117] uart_change_speed+0x64/0x160
[ 54.928119] uart_resume_port
...
So the baud rate is not restored after S3 and breaks the apps who use
UART, for example, console and bluetooth etc.
We address this issue by setting the baud rate irrespective of arg
"old", just like the drivers for other 8250 IPs. This is tested with
Intel Broxton platform.
Signed-off-by: Chen Hu <hu1.chen@intel.com>
Fixes: 4e26b134bd ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since we have port name stored in struct uart_port, we better to use
that one instead of open coding.
This will make it one place source for easier maintenance or
modifications.
While here, replace printk_ratelimited(KERN_INFO ) by pr_info_ratelimited().
It seems last printk() call in 8250_port.c.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Describe all memebers in struct exar8250_board, otherwise we get a warning:
drivers/tty/serial/8250/8250_exar.c:122: warning: Function parameter or member 'has_slave' not described in 'exar8250_board'
drivers/tty/serial/8250/8250_exar.c:122: warning: Function parameter or member 'setup' not described in 'exar8250_board'
drivers/tty/serial/8250/8250_exar.c:122: warning: Function parameter or member 'exit' not described in 'exar8250_board'
No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Exar UARTs by default supports only up to 8 channels,
all above go as extension. Thus, there is no need to have
an additional property to distinguish them from first ones.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Renesas RZ/N1 UART is based on the Synopsys DW UART, but has additional
registers for DMA. This patch does not address the changes required for DMA
support, it simply adds the compatible string.
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the IRQ controller is not yet probed do not proceed with irq=0,
try to defer the probe.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Don't dispose IRQ mapping before it has been created.
Fixes: aa9594740 ("serial: 8250_of: Add IO space support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For Synopsys DesignWare 8250 uart which version >= 4.00a, there's a
valid divisor latch fraction register. The fractional divisor width is
4bits ~ 6bits.
Now the preparation is done, it's easy to add the feature support.
This patch firstly tries to get the fractional divisor width during
probe, then setups dw specific get_divisor() and set_divisor() hook.
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some drivers could call serial8250_do_set_divisor() to complete its
own set_divisor routine. Export this symbol for code reusing.
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add these two hooks so that they can be overridden with driver specific
implementations.
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At over 4000 #includes, <linux/platform_device.h> is the 9th most
#included header file in the Linux kernel. It does not need
<linux/mod_devicetable.h>, so drop that header and explicitly add
<linux/mod_devicetable.h> to source files that need it.
4146 #include <linux/platform_device.h>
After this patch, there are 225 files that use <linux/mod_devicetable.h>,
for a reduction of around 3900 times that <linux/mod_devicetable.h>
does not have to be read & parsed.
225 #include <linux/mod_devicetable.h>
This patch was build-tested on 20 different arch-es.
It also makes these drivers SubmitChecklist#1 compliant.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com> # drivers/media/platform/vimc/
Reported-by: kbuild test robot <lkp@intel.com> # drivers/pinctrl/pinctrl-u300.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are several extended (in comparison to the traditional 16550)
registers are present in Synopsys DesignWare UART. All of them
are 32-bit ones.
Introduce helpers to simplify access to them and convert existing users.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Align serial8250_get_divisor() with serial8250_set_divisor() to accept
uart_port pointer as the first parameter. No functionality changes.
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After the commit
7d8905d064 ("serial: 8250_pci: Enable device after we check black list")
pure serial multi-port cards, such as CH355, got blacklisted and thus
not being enumerated anymore. Previously, it seems, blacklisting them
was on purpose to shut up pciserial_init_one() about record duplication.
So, remove the entries from blacklist in order to get cards enumerated.
Fixes: 7d8905d064 ("serial: 8250_pci: Enable device after we check black list")
Reported-by: Matt Turner <mattst88@gmail.com>
Cc: Sergej Pupykin <ml@sergej.pp.ru>
Cc: Alexandr Petrenko <petrenkoas83@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-and-Tested-by: Matt Turner <mattst88@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When pcmcia_loop_config fails, the lack of error-handling code may
cause unexpected results.
This patch adds error-handling code after calling pcmcia_loop_config.
Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AM654 uses a UART controller that is compatible (partially) with
existing 8250 UART, however, has a few differences with respect to DMA
support and control paths. Introduce a base definition that allows us
to build up the differences in follow on patches.
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Vignesh R <vigneshr@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the non-board-specific part of the RS485 initialization from
iot2040_rs485_config function to a new generic function used also for
other boards.
This allows using TIOCGRS485 and TIOCSRS485 on boards (such as mPCIe
serial IO modules) which are hard-wired to RS485 or have jumpers for
their configurations.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using kgdb, you get an abort when accessing the UART registers.
This is because the driver has already entered runtime PM and so turned
off the bus clock needed to access the registers.
To fix this, set the capability indicating Runtime PM is active while idle.
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I noticed that unused UARTs won't necessarily idle properly always
unless at least one byte tx transfer is done first.
After some debugging I narrowed down the problem to the scr register
dma configuration bits that need to be set before softreset for the
clocks to idle. Unless we do this, the module clkctrl idlest bits
may be set to 1 instead of 3 meaning the clock will never idle and
is blocking deeper idle states for the whole domain.
This might be related to the configuration done by the bootloader
or kexec booting where certain configurations cause the 8250 or
the clkctrl clock to jam in a way where setting of the scr bits
and reset is needed to clear it. I've tried diffing the 8250
registers for the various modes, but did not see anything specific.
So far I've only seen this on omap4 but I'm suspecting this might
also happen on the other clkctrl using SoCs considering they
already have a quirk enabled for UART_ERRATA_CLOCK_DISABLE.
Let's fix the issue by configuring scr before reset for basic dma
even if we don't use it. The scr register will be reset when we do
softreset few lines after, and we restore scr on resume. We should
do this for all the SoCs with UART_ERRATA_CLOCK_DISABLE quirk flag
set since the ones with UART_ERRATA_CLOCK_DISABLE are all based
using clkctrl similar to omap4.
Looks like both OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL
bits are needed for the clkctrl to idle after a softreset.
And we need to add omap4 to also use the UART_ERRATA_CLOCK_DISABLE
for the related workaround to be enabled. This same compatible
value will also be used for omap5.
Fixes: cdb929e445 ("serial: 8250_omap: workaround errata around idling UART after using DMA")
Cc: Keerthy <j-keerthy@ti.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Altera 16550 UART core supports FCR Rx Trigger Level setting,
but the port definition in the driver is missing the rxtrig_bytes
array specifying the trigger levels. Add the array to make the Rx
Trigger Level setting available on this type of 16550 UART.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "unthrottle_timeout" is HZ/10 but mod_timer() takes a the actual
jiffie where you want it to timeout, not an offset.
Fixes: 5909c0bf9c ("serial/aspeed-vuart: Implement quick throttle mechanism")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the 8250_of driver only supports MEM IO type
accesses.
Some development boards (Huawei D03, specifically) require
IO space access for 8250-compatible OF driver support, so
add it.
The modification is quite simple: just set the port iotype
and associated flags depending on the device address
resource type.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
device->baud is always non zero value because it is checked already in
early_serial8250_setup() before init_port is called.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Although we populate the ->throttle and ->unthrottle UART operations,
these may not be called until the ldisc has had a chance to schedule and
check buffer space. This means that we may overflow the flip buffers
without ever hitting the ldisc's throttle threshold.
This change implements an interrupt-based throttle, where we check for
space in the flip buffers before reading characters from the UART's
FIFO. If there's no space available, we disable the RX interrupt and
schedule a timer to check for space later.
For this, we need an unlocked version of the set_throttle function to be
able to change throttle state from the irq_handler, which already holds
port->lock.
This prevents a case where we drop characters under heavy RX load.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The aspeed VUART runs at LPC bus frequency, rather than being restricted
to a typical UART baud rate. This means that the VUART can receive a lot
of data, which can overrun tty flip buffers, and/or cause a large amount
of interrupt traffic.
This change implements the uart_port->throttle & unthrottle callbacks,
implemented by disabling the receiver line status & received data
available IRQs.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, we export serial8250_rx_chars, which does a whole bunch of
reads from the 8250 data register, without any form of flow control
between reads.
An upcoming change to the aspeed vuart driver implements more
fine-grained flow control in the interrupt handler, requiring
character-at-a-time control over the rx path.
This change exports serial8250_read_char to allow this.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On some systems IRQ lines between multiple UARTs might be shared. If so, the
irqflags have to be configured accordingly. The reason is: The 8250 port startup
code performs IRQ tests *before* the IRQ handler for that particular port is
registered. This is performed in serial8250_do_startup(). This function checks
whether IRQF_SHARED is configured and only then disables the IRQ line while
testing.
This test is performed upon each open() of the UART device. Imagine two UARTs
share the same IRQ line: On is already opened and the IRQ is active. When the
second UART is opened, the IRQ line has to be disabled while performing IRQ
tests. Otherwise an IRQ might handler might be invoked, but the the IRQ itself
cannot be handled, because the corresponding handler isn't registered,
yet. That's because the 8250 code uses a chain-handler and invokes the
corresponding port's IRQ handling rountines himself.
Unfortunately this IRQF_SHARED flag isn't configured for UARTs probed via device
tree even if the IRQs are shared. This way, the actual and shared IRQ line isn't
disabled while performing tests and the kernel correctly detects a spurious
IRQ. So, adding this flag to the DT probe solves the issue.
Note: The UPF_SHARE_IRQ flag is configured unconditionally. Therefore, the
IRQF_SHARED flag can be set unconditionally as well.
Example stacktrace by performing echo 1 > /dev/ttyS2 on a non-patched system:
|irq 85: nobody cared (try booting with the "irqpoll" option)
| [...]
|handlers:
|[<ffff0000080fc628>] irq_default_primary_handler threaded [<ffff00000855fbb8>] serial8250_interrupt
|Disabling IRQ #85
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable/Clear module level UART wakeup in UART_OMAP_WER register based on
return value of device_may_wakeup() in .suspend(). This allows
userspace to use sysfs to control the ability of UART to wakeup the
system from deep sleep state. Register is restored back in .startup()
call that happens as part of resume sequence.
With this patch, userspace can control UART wakeup capability via sysfs:
To enable wakeup capability:
echo enabled > /sys/class/tty/ttyXX/device/power/wakeup
For disabling wakeup capability:
echo disabled > /sys/class/tty/ttyXX/device/power/wakeup
Note that the UART wakeup events configured in the 8250 hardware only
work for idle modes that do not cut off power for the UART. For deeper
idle states, dedicated padconf wakeirqs must be used. Or in some cases
the UART RX pin can be remuxed to GPIO input if the GPIO block stays
powered.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The previous implementation has had a detrimental effect on devices using
high bitrates (bluetooth), as the fifo being non-empty for a single check
would result in a 10 µs delay.
Limit the change to devices with the new "marvell,armada-38x-uart"
compatible string. Also update the code to allow the first 1000 retries
to not perform a delay.
The maximum duration of retries has been increased to cover a worst-case
seen on the Armada 385 SoC. "dmesg ; resize", will fill the buffer with
text to output before doing a resize. At 9600 baud this took up to 13 ms
to flush all characters and avoid some getting lost.
Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for two MEN UARTs (16z025 and 16z057) to the
8250_men_mcb driver.
The 16z025 consists of up to four ports, the 16z057 has
exactly four ports. Apart from that, all of them share the
Port settings.
Signed-off-by: Michael Moese <mmoese@suse.de>
Reported-by: Ben Turner <ben.turner@21net.com>
Tested-by: Ben Turner <ben.turner@21net.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Nuvoton UART is almost compatible with the 8250 driver when probed
via the 8250_of driver, however it requires some extra configuration
at startup.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Special settings for APMC0D08 are applied when device is present
in the system. To check its presence we may use acpi_dev_present()
instead of current open coded variant.
Cc: Feng Kan <fkan@apm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI ID database is for IDs used across several drivers.
Here is the case for SUNIX combo cards.
No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
