Update serial aliases from "ttyASN" to more common "serialN".
Since dtc v1.4.6-9-gaadd0b65c987, aliases property name must
be lowercase only. This allows to fix following dtc warnings:
arch/arm/boot/dts/stih418-b2199.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
arch/arm/boot/dts/stih407-b2120.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
arch/arm/boot/dts/stih410-b2260.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
arch/arm/boot/dts/stih410-b2120.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since dtc v1.4.6-9-gaadd0b65c987, aliases property name
must include only lowercase and '-'.
After having updated all STi boards serial aliases from "ttyASN"
to "serialN", st-asc driver need to be updated accordingly as tty
aliases id is retrieved using of_alias_get_id().
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds tests to check:
- bind-mounts from /dev/pts/ptmx to /dev/ptmx work
- non-standard mounts of devpts work
- bind-mounts of /dev/pts/ptmx to locations that do not resolve to a valid
slave pty path under the originating devpts mount fail
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Most libcs will still look at /dev/ptmx when opening the master fd of a pty
device. When /dev/ptmx is a bind-mount of /dev/pts/ptmx and the TIOCGPTPEER
ioctl() is used to safely retrieve a file descriptor for the slave side of
the pty based on the master fd, the /proc/self/fd/{0,1,2} symlinks will
point to /. A very simply reproducer for this issue presupposing a libc
that uses TIOCGPTPEER in its openpty() implementation is:
unshare --mount
mount --bind /dev/pts/ptmx /dev/ptmx
chmod 666 /dev/ptmx
script
ls -al /proc/self/fd/0
Having bind-mounts of /dev/pts/ptmx to /dev/ptmx not working correctly is a
regression. In addition, it is also a fairly common scenario in containers
employing user namespaces.
The reason for the current failure is that the kernel tries to verify the
useability of the devpts filesystem without resolving the /dev/ptmx
bind-mount first. This will lead it to detect that the dentry is escaping
its bind-mount. The reason is that while the devpts filesystem mounted at
/dev/pts has the devtmpfs mounted at /dev as its parent mount:
21 -- -- / /dev
-- 21 -- / /dev/pts
devtmpfs and devpts are on different devices
-- -- 0:6 / /dev
-- -- 0:20 / /dev/pts
This has the consequence that the pathname of the parent directory of the
devpts filesystem mount at /dev/pts is /. So if /dev/ptmx is a bind-mount
of /dev/pts/ptmx then the /dev/ptmx bind-mount and the devpts mount at
/dev/pts will end up being located on the same device which is recorded in
the superblock of their vfsmount. This means the parent directory of the
/dev/ptmx bind-mount will be /ptmx:
-- -- ---- /ptmx /dev/ptmx
Without the bind-mount resolution patch the kernel will now perform the
bind-mount escape check directly on /dev/ptmx. The function responsible for
this is devpts_ptmx_path() which calls pts_path() which in turn calls
path_parent_directory(). Based on the above explanation,
path_parent_directory() will yield / as the parent directory for the
/dev/ptmx bind-mount and not the expected /dev. Thus, the kernel detects
that /dev/ptmx is escaping its bind-mount and will set /proc/<pid>/fd/<nr>
to /.
This patch changes the logic to first resolve any bind-mounts. After the
bind-mounts have been resolved (i.e. we have traced it back to the
associated devpts mount) devpts_ptmx_path() can be called. In order to
guarantee correct path generation for the slave file descriptor the kernel
now requires that a pts directory is found in the parent directory of the
ptmx bind-mount. This implies that when doing bind-mounts the ptmx
bind-mount and the devpts mount should have a common parent directory. A
valid example is:
mount -t devpts devpts /dev/pts
mount --bind /dev/pts/ptmx /dev/ptmx
an invalid example is:
mount -t devpts devpts /dev/pts
mount --bind /dev/pts/ptmx /ptmx
This allows us to support:
- calling open on ptmx devices located inside non-standard devpts mounts:
mount -t devpts devpts /mnt
master = open("/mnt/ptmx", ...);
slave = ioctl(master, TIOCGPTPEER, ...);
- calling open on ptmx devices located outside the devpts mount with a
common ancestor directory:
mount -t devpts devpts /dev/pts
mount --bind /dev/pts/ptmx /dev/ptmx
master = open("/dev/ptmx", ...);
slave = ioctl(master, TIOCGPTPEER, ...);
while failing on ptmx devices located outside the devpts mount without a
common ancestor directory:
mount -t devpts devpts /dev/pts
mount --bind /dev/pts/ptmx /ptmx
master = open("/ptmx", ...);
slave = ioctl(master, TIOCGPTPEER, ...);
in which case save path generation cannot be guaranteed.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hoist the check whether we have already found a suitable devpts filesystem
out of devpts_ptmx_path() in preparation for the devpts bind-mount
resolution patch. This is a non-functional change.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
In case of Alphascale ASM9260 probe() enables s->clk and s->clk_ahb
via mxs_get_clks(), but there is no disable of the clocks.
The patch adds it to error paths and to mxs_auart_remove().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: 254da0d753 ("serial: mxs-auart: add Alphascale ASM9260 support")
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>
Having a fixed prefix helps at several places. It ensures that another
driver doesn't use the same function name which confuses the linker and
tools like ctags. It simplifies working with function tracing and
dynamic printk() support which can filter on function names. And last
but not least it helps the human source code reader to understand if a
given function belongs to a driver or a more general part of the kernel.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial_core might call the .start_tx callback without any data being
available to send. In this case return early instead of going through
all the setup needed for sending which might include disabling RX in
RS485 half-duplex mode.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using RS485 half duplex the Transmitter Complete irq is needed to
determine the moment when the transmitter can be disabled. When using
DMA this irq must only be enabled when DMA has completed to transfer all
data. Otherwise the CPU might busily trigger this irq which is not
properly handled and so the also pending irq for the DMA transfer cannot
trigger.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows to increase the RX waterlevel which allows to delay the RRDY
irq. The desired effect is that less irqs are needed to handle
characters and so reduce irq count of the system.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure that UCR1.RXDMAEN and UCR1.ATDMAEN (for the DMA case) and
UCR1.RRDYEN (for the PIO case) are off iff UCR1.RXEN is disabled. This
ensures that the fifo isn't read with RX disabled which results in an
exception.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the UART is used in DMA mode, .stop_rx() does nothing if the port
isn't suspended. This is wrong as .stop_rx() should stop receiving
characters unconditionally. When the port is about to be closed the DMA
channel is stopped in .shutdown(), so this isn't necessary to be in
.stop_rx() here, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The aging timer fires if there are characters in the RX fifo but the
water level isn't reached yet. Make sure that the waterlevel is
configured before the aging timer is enabled to trigger a DMA request
(UCR1_ATDMAEN).
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial/imx driver is full of inconsistently named and typed
variables that hold different register values.
Consistently use u32 as type (matching what readl and writel use) and
name the variables after the register whose value they are holding.
This makes it easier to notice when UCR2_RTSEN is written to UCR1.
The only difference introduced by this commit in the compiled driver is
that twice the second argument to warn_slowpath_null() changed because the
two WARN_ON in dma_rx_callback() pass __LINE__ to warn_slowpath_null().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The original code looks as follows:
if (sport->dma_is_enabled) {
... make sure TX DMA is running, i.e. .dma_is_txing = 1
}
if (sport->dma_is_txing)
return;
As .dma_is_txing can only be true if .dma_is_enabled is, the return can
go at the end of the first if body without an additional check.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Neither .dma_is_txing nor .dma_is_rxing can evaluate to true if
.dma_is_enabled evaluates to false:
The only function that sets .dma_is_txing to a non-zero value is
imx_dma_tx() which is only called if .dma_is_enabled is true. Same for
.dma_is_rxing and start_rx_dma(). And before .dma_is_enabled is set to 0
when imx_shutdown calls imx_disable_dma(), .dma_is_rxing and
.dma_is_txing are reset to zero before, too.
For this reason
sport->dma_is_enabled && sport->dma_is_rxing
has the same value as
sport->dma_is_rxing
which allows to simplify three if conditions.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reduces the amount of read accesses to the register space by
shadowing the values for five registers that only change on writing
them. There is a single bit in UCR2 that might change without being
written to it, this is handled accordingly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This prepares implementing shadow copies for the control registers and
additionally provides a good place to hook in debug code to trace
register usage.
Most of this patch was done using pattern substitution:
perl -p -i -e '
s/\breadl(?:_relaxed)?\((?:sport->port\.|port->)membase \+/imx_uart_readl(sport,/;
s/\bwritel(?:_relaxed)?\(([^,]*), (sport->port\.|port->)membase \+/imx_uart_writel(sport, $1,/;
' drivers/tty/serial/imx.c
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The RISC-V ISA defines a simple console that is availiable via SBI calls
on all systems. The SBI console is designed to be availiable at all
times, so while it's most natural to use this as an early printk target
it's also possible to use this as the system console when there isn't a
better one availiable.
This patch adds support for the RISC-V SBI console via the HVC
infastructure. It's entirely independent from our early printk support,
which results in early boot messages appearing twice over the SBI
console. As far as I can tell that's the fault of our early printk
support (we should support earlycon) as opposed to this driver.
There is one checkpatch.pl warning here: to check the MAINTAINERS file.
They're all matched by the "K: riscv" line.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Consistently indicate being called with irqs off and the port lock taken
for all functions that this applies to.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Only the reference manual for the i.MX1 (I have MC9328MX1RM/D Rev 5 from
2004) uses TDMAEN and RDMAEN for these. All reference manuals for the
newer chips use TXDMAEN and RXDMAEN. Update to the newer name with the
assumption that most imx users don't use an imx1 any more.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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>
The cdns_uart_port[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.
Fix this by adding a range check.
Fixes: 928e926349 ("tty: xuartps: Initialize ports according to aliases")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sirf_ports[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.
Fix this by adding a range check.
Fixes: a6ffe8966a ("serial: sirf: use dynamic method allocate uart structure")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sci_ports[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.
Fix this by adding a range check.
Note that the array size is defined by a Kconfig symbol
(CONFIG_SERIAL_SH_SCI_NR_UARTS), so this can even be triggered using a
legitimate DTB.
Fixes: 97ed9790c5 ("serial: sh-sci: Remove unused platform data capabilities field")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The s3c24xx_serial_ports[] array is indexed using a value derived from
the "serialN" alias in DT, or from an incrementing probe index, which
may lead to an out-of-bounds access.
Fix this by adding a range check.
Note that the array size is defined by a Kconfig symbol
(CONFIG_SERIAL_SAMSUNG_UARTS), so this can even be triggered using
a legitimate DTB or legitimate board code.
Fixes: 13a9f6c64f ("serial: samsung: Consider DT alias when probing ports")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial_pxa_ports[] array is indexed using a value derived from the
"serialN" alias in DT, or from platform data, which may lead to an
out-of-bounds access.
Fix this by adding a range check.
Fixes: 699c20f3e6 ("serial: pxa: add OF support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The auart_port[] array is indexed using a value derived from the
"serialN" alias in DT, or from platform data, which may lead to an
out-of-bounds access.
Fix this by adding a range check.
Fixes: 1ea6607d4c ("serial: mxs-auart: Allow device tree probing")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The imx_ports[] array is indexed using a value derived from the
"serialN" alias in DT, or from platform data, which may lead to an
out-of-bounds access.
Fix this by adding a range check.
Fixes: ff05967a07 ("serial/imx: add of_alias_get_id() reference back")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lpuart_ports[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.
Fix this by adding a range check.
Fixes: c9e2e946fb ("tty: serial: add Freescale lpuart driver support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The arc_uart_ports[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.
Fix this by adding a range check.
Note that the array size is defined by a Kconfig symbol
(CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a
legitimate DTB.
Fixes: ea28fd56fc ("serial/arc-uart: switch to devicetree based probing")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
imx_shutdown() calls imx_disable_dma if .dma_is_enabled. So after
imx_shudown() completes, .dma_is_enabled is zero. For this reason
.dma_is_enabled is also zero when imx_startup() is called. So the check
for this variable being zero can be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The .dma_is_inited member is only set to a value != 0 when the port's
startup function calls imx_uart_dma_init(). On shutdown of the port
imx_uart_dma_exit is called which sets the value back to 0. So
.dma_is_inited is always 0 when imx_startup() is called (assuming
.startup() and .shutdown() are correctly balanced) and the check for
!sport->dma_is_inited can go away.
This allows to replace .dma_is_inited by a variable local to
imx_startup.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Handling an irq that isn't enabled can have some undesired side effects.
Some of these are mentioned in the newly introduced code comment. Some
of the irq sources already had their handling right, some don't. Handle
them all in the same consistent way.
The change for USR1_RRDY and USR1_AGTIM drops the check for
dma_is_enabled. This is correct as UCR1_RRDYEN and UCR2_ATEN are always
off if dma is enabled.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now the variable holding the value of register USR1 is called usr1
instead of sts which is more straight forward. The same is also done for
sts2 which is called usr2 now.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The check sts & USR1_DTRD was just evaluated to true two lines above.
So this change doesn't have any effect on the semantic of the driver.
Fixes: 27e1650105 ("serial: imx: implement DSR irq handling for DTE mode")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bit pattern STAT_FRM_ERR is being bit-wise or'd twice; remove the
redundant 2nd STAT_FRM_ERR
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows me to login after sending a break when service
serial-getty@ttymxc0.service is running
The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors
fixes this by allowing the higher layers to see a break.
Also, call uart_handle_break to handle possible
"secure attention key."
FYI: Martin said the ROM sdma firmware works with this patch,
but external sdma firmware still does not send breaks on a
i.mx6UL
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Tested-by: Martin Hicks <mort@bork.org>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An issue has been observed on the Marvell Armada 38x serial port.
Writes to UART_LCR can result in characters that are currently held in the
TX FIFO being lost rather than sent, even if the userspace process has
attempted to flush them.
This is most visible when using the "resize" command (tested on Busybox),
where we have observed the escape code for restoring cursor position
becoming mangled.
Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
High latencies of classic timers cause performance issues for high-
speed serial transmissions. This patch transforms rx_timer into an
hrtimer to reduce the minimum latency.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
omap_8250_throttle() is called when tty RX buffer is about to overflow
and can no longer keep up with the rate at which UART is receiving data.
So, the expectation of this callback, is that UART stops RX and asserts
HW flow control to signal the sender to stop sending more data.
omap_8250_throttle() disables RX FIFO interrupts thus FIFO is no longer
serviced, leading to assertion of flow control once RX FIFO is full.
But, this does not work when DMA is enabled as driver keeps queuing new
RX DMA request in completion handler without brothering about throttling
request made by the higher layer.
This patch introduces a flag that can be used to determine whether or
not to queue next RX DMA request based on throttling request.
Without this patch, tty buffer overflows are reported at higher
baudrates.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, data in RX FIFO is read based on UART_LSR register state even
if RDI and RLSI interrupts are disabled in UART_IER register.
This is because when IRQ handler is called due to TX FIFO empty event,
RX FIFO is serviced based on UART_LSR register status instead of
UART_IIR status. This defeats the purpose of disabling UART RX
FIFO interrupts during throttling(see, omap_8250_throttle()) as IRQ
handler continues to drain UART RX FIFO resulting in overflow of buffer
at tty layer.
Fix this by making sure that driver drains UART RX FIFO only when
UART_IIR_RDI is set along with UART_LSR_BI or UART_LSR_DR bits.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
R-Car V3H (R8A77980) SoC has the R-Car gen3 compatible SCIF and HSCIF ports,
so document the SoC specific bindings.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some debugging tools (/sys/kernel/debug/gpio, `lsgpio`) use the
gpio_chip's label for displaying an additional context. Right now, the
information duplicates stuff which is already available from the
parent's device. This is how e.g. `lsgpio`'s output looks like:
GPIO chip: gpiochip2, "spi1.2", 16 GPIO lines
Comparing the output of other GPIO expanders that I have available:
gpiochip4: GPIOs 464-479, parent: spi/spi1.1, mcp23s17, can sleep:
gpiochip5: GPIOs 448-463, parent: i2c/0-0020, pca9555, can sleep:
gpiochip2: GPIOs 496-511, parent: spi/spi1.2, spi1.2, can sleep:
This patch ensures that the type of the real HW device is shown instead
of duplicating the SPI path:
gpiochip2: GPIOs 496-511, parent: spi/spi1.2, MAX14830, can sleep:
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UART can be operated without an irq. In this case a timer is setup
that regularily calls altera_uart_interrupt(). The receiving part
depends on pp->imr having the bit ALTERA_UART_STATUS_RRDY_MSK set,
otherwise altera_uart_rx_chars() is never called. So ensure that the bit
gets set (disguised as ALTERA_UART_CONTROL_RRDY_MSK) by not returning
early from altera_uart_startup() if port->irq is 0.
This doesn't affect the hardware as the ALTERA_UART_CONTROL_RRDY_MSK bit
isn't actually written to the control register.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
