Commit e490c9144c ("tty: Add software emulated RS485 support for 8250")
introduced support to use RTS as an rs485 Transmit Enable signal.
Drivers opt in to the feature by calling serial8250_em485_init() from
their ->rs485_config() callback.
So far there are two drivers doing that, 8250_omap.c and 8250_of.c.
Both use an identical callback. We're about to add a third user of that
callback, therefore deduplicate it and move it to 8250_port.c.
Drivers now opt in to rs485 software emulation by assigning the generic
serial8250_rs485_config() callback introduced herein to their
.rs485_config struct member. This change allows unexporting
serial8250_em485_init() and declaring it static.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Matwey V. Kornilov <matwey@sai.msu.ru>
Cc: Heiko Schocher <hs@denx.de>
Link: https://lore.kernel.org/r/fcef63642dc4eae41ae7842d23747b2bf5d40285.1582895077.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_do_set_mctrl() currently allows modifying the RTS modem
control line even when RTS is used as an rs485 Transmit Enable signal.
It is thus possible for user space to interfere with rs485 communication
by invoking a TIOCMSET ioctl().
Ignore such change requests and retain the current RTS polarity when in
rs485 mode. Note that serial8250_set_mctrl() is always called with
port->lock held, so there's no risk that RTS is changed concurrently.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Matwey V. Kornilov <matwey@sai.msu.ru>
Link: https://lore.kernel.org/r/b1ce34ca9bc4d7bdc6e9852fcf30b1f4e37c8a80.1582895077.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a driver exposes early consoles with EARLYCON_DECLARE() and
OF_EARLYCON_DECLARE(), pefer the non-OF variant if the user specifies it
by
earlycon=<driver>,<options>
The rationale behind this is that some drivers register multiple setup
functions under the same driver name. Eg.
OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
It depends on the order of the entries which console_setup() actually
gets called. To make things worse, I guess it also depends on the
compiler how these are ordered. Thus always prefer the EARLYCON_DECLARE()
ones.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200220174607.24285-1-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 3bc3206e1c ("serial: fsl_lpuart: Remove the alias node
dependence") the port line number can also be allocated by IDA, but in
case of an error the ID will no be removed again. More importantly, any
ID will be freed in remove(), even if it wasn't allocated but instead
fetched by of_alias_get_id(). If it was not allocated by IDA there will
be a warning:
WARN(1, "ida_free called for id=%d which is not allocated.\n", id);
Move the ID allocation more to the end of the probe() so that we still
can use plain return in the first error cases.
Fixes: 3bc3206e1c ("serial: fsl_lpuart: Remove the alias node dependence")
Signed-off-by: Michael Walle <michael@walle.cc>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200303174306.6015-3-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a659652f61.
This broke the earlycon on LS1021A processors because the order of the
earlycon_setup() functions were changed. Before the commit the normal
lpuart32_early_console_setup() was called. After the commit the
lpuart32_imx_early_console_setup() is called instead.
Fixes: a659652f61 ("tty: serial: fsl_lpuart: drop EARLYCON_DECLARE")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200303174306.6015-2-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Apple devices the _CRS method returns an empty resource template, and
the resource settings are instead provided by the _DSM method. But
commit 33364d63c7 (serdev: Add ACPI
devices by ResourceSource field) changed the search for serdev devices
to require valid, non-empty resource template, thereby breaking Apple
devices and causing bluetooth devices to not be found.
This expands the check so that if we don't find a valid template, and
we're on an Apple machine, then just check for the device being an
immediate child of the controller and having a "baud" property.
Cc: <stable@vger.kernel.org> # 5.5
Fixes: 33364d63c7 ("serdev: Add ACPI devices by ResourceSource field")
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
Link: https://lore.kernel.org/r/20200211194723.486217-1-ronald@innovation.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The peripheral has support for inverting its input and/or output
signals. This is useful if the hardware flips polarity of the
peripheral's signal, such as swapped +/- pins on an RS-422 transceiver,
or an inverting level shifter. Add support for these control registers
via the device tree binding.
As part of this change, make the writes of the various registers more
uniform by moving the UCR3 block up near the other registers' blocks,
since the INVT bit must be set before enabling the peripheral.
Signed-off-by: George Hilliard <ghilliard@kopismobile.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20200226222319.18383-3-ghilliard@kopismobile.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move all the selection global variables to a structure vc_selection,
instantiated as vc_sel. This helps to group all the variables together
and see what should be protected by the embedded lock too.
It might be used later also for per-console selection support.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219073951.16151-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
use_unicode needs not be global. It is used only in set_selection_kernel
and sel_pos (a callee). It is also always set there prior calling
sel_pos. So make use_unicode local and rename it to plain shorter
"unicode". Finally, propagate it to sel_pos via parameter.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219073951.16151-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
multiplier and mode are not actually needed:
* multiplier is used only in kmalloc_array, so use "use_unicode ? 4 : 1"
directly
* mode is used only to assign a bool in this manner:
if (cond)
x = true;
else
x = false;
So do "x = cond" directly.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219073951.16151-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Variables declared in a switch statement before any case statements
cannot be automatically initialized with compiler instrumentation (as
they are not part of any execution flow). With GCC's proposed automatic
stack variable initialization feature, this triggers a warning (and they
don't get initialized). Clang's automatic stack variable initialization
(via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also
doesn't initialize such variables[1]. Note that these warnings (or silent
skipping) happen before the dead-store elimination optimization phase,
so even when the automatic initializations are later elided in favor of
direct initializations, the warnings remain.
To avoid these problems, move such variables into the "case" where
they're used or lift them up into the main function body.
drivers/tty/n_tty.c: In function ‘__process_echoes’:
drivers/tty/n_tty.c:657:18: warning: statement will never be executed [-Wswitch-unreachable]
657 | unsigned int num_chars, num_bs;
| ^~~~~~~~~
[1] https://bugs.llvm.org/show_bug.cgi?id=44916
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200220062313.69209-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We got rid of backup_tty recently. Also, the tty layer ensures not to
call other ldisc hooks after ldisc close. That means, all those tests
are superfluous now so remove them.
Note that we remove the magic check in write after schedule too. The tty
cannot change during schedule.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219084118.26491-14-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_hdlc_release contains four loops to free each buffer list. Create a
helper (n_hdlc_free_buf_list) and call it for every list instead. It
makes n_hdlc_release more readable.
We are switching from "for (;;)" to "do {} while (buf)" which avoids the
"if (buf)" completely -- kfree is a nop for NULL pointers.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219084118.26491-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
