The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
simplify the logic. Those look scary to checkpatch because they contain
ifs without do-while loops.
Avoid the macros by creating small equivalent static functions; that
lets the compiler do its type checking & avoids checkpatch errors.
For the second instance __assign_bit is not usable because it deals with
unsigned long pointers whereas we have an unsigned int in
pl011_set_mctrl.
This addresses the following checkpatch warnings:
$ ./scripts/checkpatch.pl --strict --file \
drivers/tty/serial/amba-pl011.c
ERROR: Macros starting with if should be enclosed by a do -
while loop to avoid possible if/else logic defects
CHECK: Macro argument 'uartbit' may be better as '(uartbit)' to
avoid precedence issues
ERROR: Macros starting with if should be enclosed by a do - while
loop to avoid possible if/else logic defects
CHECK: Macro argument 'tiocmbit' may be better as '(tiocmbit)' to
avoid precedence issues
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-3-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Follow recommandations from:
$ ./scripts/checkpatch.pl --strict --file \
drivers/tty/serial/amba-pl011.c
We fix 5 warnings and 48 checks, all related to whitespace.
Culprits are:
CHECK: Alignment should match open parenthesis
CHECK: Blank lines aren't necessary after an open brace '{'
CHECK: Lines should not end with a '('
CHECK: Please don't use multiple blank lines
CHECK: Please use a blank line after function/struct/union/enum
declarations
CHECK: spaces preferred around that '/' (ctx:VxV)
CHECK: spaces preferred around that '|' (ctx:VxV)
WARNING: Missing a blank line after declarations
WARNING: please, no spaces at the start of a line
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-2-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It can happen that while a break is received the transmitter gets empty
and IIR signals a Transmitter holding register empty (THRI) event. In
this case it's too early for the break workaround. Still doing it then
results in the THRI event not being rereported which makes the driver
miss that and e.g. for RS485 half-duplex communication it fails to
switch back to RX mode.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231213174312.2341013-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit cc4c1d05eb ("sc16is7xx: Properly resume TX after stop") changed
behavior to unconditionnaly set the THRI interrupt in sc16is7xx_tx_proc().
For example when sending a 65 bytes message, and assuming the Tx FIFO is
initially empty, sc16is7xx_handle_tx() will write the first 64 bytes of the
message to the FIFO and sc16is7xx_tx_proc() will then activate THRI. When
the THRI IRQ is fired, the driver will write the remaining byte of the
message to the FIFO, and disable THRI by calling sc16is7xx_stop_tx().
When sending a 2 bytes message, sc16is7xx_handle_tx() will write the 2
bytes of the message to the FIFO and call sc16is7xx_stop_tx(), disabling
THRI. After sc16is7xx_handle_tx() exits, control returns to
sc16is7xx_tx_proc() which will unconditionally set THRI. When the THRI IRQ
is fired, the driver simply acknowledges the interrupt and does nothing
more, since all the data has already been written to the FIFO. This results
in 2 register writes and 4 register reads all for nothing and taking
precious cycles from the I2C/SPI bus.
Fix this by enabling the THRI interrupt only when we fill the Tx FIFO to
its maximum capacity and there are remaining bytes to send in the message.
Fixes: cc4c1d05eb ("sc16is7xx: Properly resume TX after stop")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-7-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SC16IS7XX IC supports a burst mode to access the FIFOs where the
initial register address is sent ($00), followed by all the FIFO data
without having to resend the register address each time. In this mode, the
IC doesn't increment the register address for each R/W byte.
The regmap_raw_read() and regmap_raw_write() are functions which can
perform IO over multiple registers. They are currently used to read/write
from/to the FIFO, and although they operate correctly in this burst mode on
the SPI bus, they would corrupt the regmap cache if it was not disabled
manually. The reason is that when the R/W size is more than 1 byte, these
functions assume that the register address is incremented and handle the
cache accordingly.
Convert FIFO R/W functions to use the regmap _noinc_ versions in order to
remove the manual cache control which was a workaround when using the
_raw_ versions. FIFO registers are properly declared as volatile so
cache will not be used/updated for FIFO accesses.
Fixes: dfeae619d7 ("serial: sc16is7xx")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-6-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Using a static buffer inside sc16is7xx_regmap_name() was a convenient and
simple way to set the regmap name without having to allocate and free a
buffer each time it is called. The drawback is that the static buffer
wastes memory for nothing once regmap is fully initialized.
Remove static buffer and use constant strings instead.
This also avoids a truncation warning when using "%d" or "%u" in snprintf
which was flagged by kernel test robot.
Fixes: 3837a03795 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc: <stable@vger.kernel.org> # 6.1.x: 3837a03 serial: sc16is7xx: improve regmap debugfs by using one regmap per port
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The capability CAP_CHECKPOINT_RESTORE was introduced to allow non-root
users to checkpoint and restore processes as non-root with CRIU.
This change extends CAP_CHECKPOINT_RESTORE to enable the CRIU option
'--shell-job' as non-root. CRIU's man-page describes the '--shell-job'
option like this:
Allow one to dump shell jobs. This implies the restored task will
inherit session and process group ID from the criu itself. This option
also allows to migrate a single external tty connection, to migrate
applications like top.
TIOCSLCKTRMIOS can only be done if the process has CAP_SYS_ADMIN and
this change extends it to CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE.
With this change it is possible to checkpoint and restore processes
which have a tty connection as non-root if CAP_CHECKPOINT_RESTORE is
set.
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Adrian Reber <areber@redhat.com>
Acked-by: Andrei Vagin <avagin@gmail.com>
Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use preferred device_get_match_data() instead of of_match_device() to
get the driver match data. With this, adjust the includes to explicitly
include the correct headers.
Error checking for matching was not necessary as matching is always
successful if we're already in probe and the match tables always have data
pointers.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231207162632.2650356-2-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it was merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. Soon the implicit includes are going to be removed.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231207162632.2650356-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In ACM support for sending breaks to devices is optional.
If a device says that it doenot support sending breaks,
the host must respect that.
Given the number of optional features providing tty operations
for each combination is not practical and errors need to be
returned dynamically if unsupported features are requested.
In case a device does not support break, we want the tty layer
to treat that like it treats drivers that statically cannot
support sending a break. It ignores the inability and does nothing.
This patch uses EOPNOTSUPP to indicate that.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 9e98966c7b ("tty: rework break handling")
Link: https://lore.kernel.org/r/20231207132639.18250-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no in-kernel function to get the status register of a tty device
like the TIOCMGET ioctl returns to userspace. Create a new function,
tty_get_tiocm(), to obtain the status register that other portions of the
kernel can call if they need this information, and move the existing
internal tty_tiocmget() function to use this interface.
Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231127110311.3583957-2-fe@dev.tdt.de
Signed-off-by: Lee Jones <lee@kernel.org>
Refer ARM DDI 0487I.a ID081822, D17.3.8, DBGDTRTX_EL0,
"If TXfull is set to 1, set DTRRX and DTRTX to UNKNOWN"
Thus one should always check for TXfull condition before hvc can be
used as an early console. This is similar to what is being done
today in hvc_dcc_console_init() and hvc_dcc_init().
The count 0x4000000 has been obtained from uboot (v2024.01-rc3)
drivers/serial/arm_dcc.c "TIMEOUT_COUNT".
It reads the dcc status and waits for 0x4000000 times for the TX Fifo
to be available before returning an error. Thus, it will prevent DCC
to be used as early console.
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Link: https://lore.kernel.org/r/20231205123534.3376883-1-ayan.kumar.halder@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using the serial port as RS485 port, the tx statemachine is used to
control the RTS pin to drive the RS485 transceiver TX_EN pin. When the
TTY port is closed in the middle of a transmission (for instance during
userland application crash), imx_uart_shutdown disables the interface
and disables the Transmission Complete interrupt. afer that,
imx_uart_stop_tx bails on an incomplete transmission, to be retriggered
by the TC interrupt. This interrupt is disabled and therefore the tx
statemachine never transitions out of SEND. The statemachine is in
deadlock now, and the TX_EN remains low, making the interface useless.
imx_uart_stop_tx now checks for incomplete transmission AND whether TC
interrupts are enabled before bailing to be retriggered. This makes sure
the state machine handling is reached, and is properly set to
WAIT_AFTER_SEND.
Fixes: cb1a609236 ("serial: imx: implement rts delaying for rs485")
Signed-off-by: Paul Geurts <paul_geurts@live.nl>
Tested-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Tested-by: Eberhard Stoll <eberhard.stoll@gmx.de>
Link: https://lore.kernel.org/r/AM0PR09MB26758F651BC1B742EB45775995B8A@AM0PR09MB2675.eurprd09.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The console is immediately assigned to the ma35d1 port without
checking its index. This oversight can lead to out-of-bounds
errors when the index falls outside the valid '0' to
MA35_UART_NR range. Such scenario trigges ran error like the
following:
UBSAN: array-index-out-of-bounds in drivers/tty/serial/ma35d1_serial.c:555:51
index -1 is out of range for type 'uart_ma35d1_port [17]
Check the index before using it and bail out with a warning.
Fixes: 930cbf92db ("tty: serial: Add Nuvoton ma35d1 serial driver support")
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Cc: Jacky Huang <ychuang3@nuvoton.com>
Cc: <stable@vger.kernel.org> # v6.5+
Link: https://lore.kernel.org/r/20231204163804.1331415-2-andi.shyti@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Designware UART has an optional feature to enable Fractional Baud Rate
Divisor (DLF) through the FRACTIONAL_BAUD_DIVISOR_EN configuration
parameter, and it is not dependent on ADDITIONAL_FEATURES.
dw8250_setup_port() checks DLF to determine dlf_size only when UART
Component Version (UCV) is non-zero. As mentioned above DLF and UCV are
independent features. Move the logic corresponding to DLF size
calculation ahead of the UCV check to prevent early return. Otherwise,
dlf_size will be zero and driver will not be able to use the
controller's fractional baud rate divisor (DLF) feature.
Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com>
Link: https://lore.kernel.org/r/20231126160420.2442330-1-vamshigajjela@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This means:
* move outbuf to the end of struct hvc_struct and convert from pointer
to flexible array (the structure is smaller now)
* use struct_size() at the allocation site
* align outbuf in the struct instead of ALIGN() at kzalloc()
And apart from the above, use u8 instead of char (which are the same
thanks to -funsigned-char). The former is now preferred over the latter.
It makes the code easier to understand.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20231121092258.9334-12-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_write_message() has only one user: quotas. In particular, there the
use depends on CONFIG_PRINT_QUOTA_WARNING. And that is deprecated and
marked as BROKEN already too.
So make tty_write_message() dependent on that very config option. This
action in fact drops tty_write_message() from the vmlinux binary. Good
riddance.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Jan Kara <jack@suse.com>
Acked-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231121092258.9334-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
