commit f23c52aafb upstream.
Commit 7a637784d5 ("serial: imx: reduce RX interrupt frequency")
introduced a regression on the i.MX6UL EVK board. The issue can be
reproduced with the following steps:
- Open vi on the board.
- Paste a text file (~150 characters).
- Save the file, then repeat the process.
- Compare the sha256sum of the saved files.
The checksums do not match due to missing characters or entire lines.
Fix this by restoring the RXTL value to 1 when the UART is used as a
console.
This ensures timely RX interrupts and reliable data reception in console
mode.
With this change, pasted content is saved correctly, and checksums are
always consistent.
Cc: stable <stable@kernel.org>
Fixes: 7a637784d5 ("serial: imx: reduce RX interrupt frequency")
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20250619114617.2791939-1-festevam@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6bd697b5fc ]
When two instances of uart devices are probing, a concurrency race can
occur. If one thread calls uart_register_driver function, which first
allocates and assigns memory to 'uart_state' member of uart_driver
structure, the other instance can bypass uart driver registration and
call ulite_assign. This calls uart_add_one_port, which expects the uart
driver to be fully initialized. This leads to a kernel panic due to a
null pointer dereference:
[ 8.143581] BUG: kernel NULL pointer dereference, address: 00000000000002b8
[ 8.156982] #PF: supervisor write access in kernel mode
[ 8.156984] #PF: error_code(0x0002) - not-present page
[ 8.156986] PGD 0 P4D 0
...
[ 8.180668] RIP: 0010:mutex_lock+0x19/0x30
[ 8.188624] Call Trace:
[ 8.188629] ? __die_body.cold+0x1a/0x1f
[ 8.195260] ? page_fault_oops+0x15c/0x290
[ 8.209183] ? __irq_resolve_mapping+0x47/0x80
[ 8.209187] ? exc_page_fault+0x64/0x140
[ 8.209190] ? asm_exc_page_fault+0x22/0x30
[ 8.209196] ? mutex_lock+0x19/0x30
[ 8.223116] uart_add_one_port+0x60/0x440
[ 8.223122] ? proc_tty_register_driver+0x43/0x50
[ 8.223126] ? tty_register_driver+0x1ca/0x1e0
[ 8.246250] ulite_probe+0x357/0x4b0 [uartlite]
To prevent it, move uart driver registration in to init function. This
will ensure that uart_driver is always registered when probe function
is called.
Signed-off-by: Jakub Lewalski <jakub.lewalski@nokia.com>
Signed-off-by: Elodie Decerle <elodie.decerle@nokia.com>
Link: https://lore.kernel.org/r/20250331160732.2042-1-elodie.decerle@nokia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 651dee0369 upstream.
In the sh-sci driver, serial ports are mapped to the sci_ports[] array,
with earlycon mapped at index zero.
The uart_add_one_port() function eventually calls __device_attach(),
which, in turn, calls pm_request_idle(). The identified code path is as
follows:
uart_add_one_port() ->
serial_ctrl_register_port() ->
serial_core_register_port() ->
serial_core_port_device_add() ->
serial_base_port_add() ->
device_add() ->
bus_probe_device() ->
device_initial_probe() ->
__device_attach() ->
// ...
if (dev->p->dead) {
// ...
} else if (dev->driver) {
// ...
} else {
// ...
pm_request_idle(dev);
// ...
}
The earlycon device clocks are enabled by the bootloader. However, the
pm_request_idle() call in __device_attach() disables the SCI port clocks
while earlycon is still active.
The earlycon write function, serial_console_write(), calls
sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks
are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to
remain unset indefinitely, causing the while loop in sci_poll_put_char()
to never exit. On single-core SoCs, this can result in the system being
blocked during boot when this issue occurs.
To resolve this, increment the runtime PM usage counter for the earlycon
SCI device before registering the UART port.
Fixes: 0b0cced19a ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f10170699 upstream.
The early_console_setup() function initializes sci_ports[0].port with an
object of type struct uart_port obtained from the struct earlycon_device
passed as an argument to early_console_setup().
Later, during serial port probing, the serial port used as earlycon
(e.g., port A) might be remapped to a different position in the sci_ports[]
array, and a different serial port (e.g., port B) might be assigned to slot
0. For example:
sci_ports[0] = port B
sci_ports[X] = port A
In this scenario, the new port mapped at index zero (port B) retains the
data associated with the earlycon configuration. Consequently, after the
Linux boot process, any access to the serial port now mapped to
sci_ports[0] (port B) will block the original earlycon port (port A).
To address this, introduce an early_console_exit() function to clean up
sci_ports[0] when earlycon is exited.
To prevent the cleanup of sci_ports[0] while the serial device is still
being used by earlycon, introduce the struct sci_port::probing flag and
account for it in early_console_exit().
Fixes: 0b0cced19a ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7cc0e0a43a upstream.
On the Renesas RZ/G3S, when doing suspend to RAM, the uart_suspend_port()
is called. The uart_suspend_port() calls 3 times the
struct uart_port::ops::tx_empty() before shutting down the port.
According to the documentation, the struct uart_port::ops::tx_empty()
API tests whether the transmitter FIFO and shifter for the port is
empty.
The Renesas RZ/G3S SCIFA IP reports the number of data units stored in the
transmit FIFO through the FDR (FIFO Data Count Register). The data units
in the FIFOs are written in the shift register and transmitted from there.
The TEND bit in the Serial Status Register reports if the data was
transmitted from the shift register.
In the previous code, in the tx_empty() API implemented by the sh-sci
driver, it is considered that the TX is empty if the hardware reports the
TEND bit set and the number of data units in the FIFO is zero.
According to the HW manual, the TEND bit has the following meaning:
0: Transmission is in the waiting state or in progress.
1: Transmission is completed.
It has been noticed that when opening the serial device w/o using it and
then switch to a power saving mode, the tx_empty() call in the
uart_port_suspend() function fails, leading to the "Unable to drain
transmitter" message being printed on the console. This is because the
TEND=0 if nothing has been transmitted and the FIFOs are empty. As the
TEND=0 has double meaning (waiting state, in progress) we can't
determined the scenario described above.
Add a software workaround for this. This sets a variable if any data has
been sent on the serial console (when using PIO) or if the DMA callback has
been called (meaning something has been transmitted). In the tx_empty()
API the status of the DMA transaction is also checked and if it is
completed or in progress the code falls back in checking the hardware
registers instead of relying on the software variable.
Fixes: 73a19e4c03 ("serial: sh-sci: Add DMA support.")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241125115856.513642-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[claudiu.beznea: fixed conflict by:
- keeping serial_port_out() instead of sci_port_out() in
sci_transmit_chars()
- keeping !uart_circ_empty(xmit) condition in sci_dma_tx_complete(),
after s->tx_occurred = true; assignement]
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 81100b9a7b upstream.
On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there
are multiple ways to configure the requested serial speed. If firmware
uses a different method than Linux, and if any debug info is printed
after the Bit Rate Register (SCBRR) is restored, but before termios is
reconfigured (which configures the alternative method), the system may
lock-up during resume.
Fix this by saving and restoring the contents of the BRG Frequency
Division (SCDL) and Clock Select (SCCKS) registers as well.
Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which
configures the sampling point, and the SCIFA/SCIFB's Serial Port Control
and Data Registers (SCPCR/SCPDR), which configure the optional control
flow signals.
After this, all registers that are not saved/restored are either:
- read-only,
- write-only,
- status registers containing flags with clear-after-set semantics,
- FIFO Data Count Trigger registers, which do not matter much for
the serial console.
Fixes: 22a6984c5b ("serial: sh-sci: Update the suspend/resume support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 22a6984c5b ]
The Renesas RZ/G3S supports a power saving mode where power to most of the
SoC components is turned off. When returning from this power saving mode,
SoC components need to be re-configured.
The SCIFs on the Renesas RZ/G3S need to be re-configured as well when
returning from this power saving mode. The sh-sci code already configures
the SCIF clocks, power domain and registers by calling uart_resume_port()
in sci_resume(). On suspend path the SCIF UART ports are suspended
accordingly (by calling uart_suspend_port() in sci_suspend()). The only
missing setting is the reset signal. For this assert/de-assert the reset
signal on driver suspend/resume.
In case the no_console_suspend is specified by the user, the registers need
to be saved on suspend path and restore on resume path. To do this the
sci_console_save()/sci_console_restore() functions were added. There is no
need to cache/restore the status or FIFO registers. Only the control
registers. The registers that will be saved/restored on suspend/resume are
specified by the struct sci_suspend_regs data structure.
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20250207113313.545432-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1bd2aad57d ]
The following splat has been observed on a SAMA5D27 platform using
atmel_serial:
BUG: sleeping function called from invalid context at kernel/irq/manage.c:738
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last enabled at (0): [<00000000>] 0x0
hardirqs last disabled at (0): [<c01588f0>] copy_process+0x1c4c/0x7bec
softirqs last enabled at (0): [<c0158944>] copy_process+0x1ca0/0x7bec
softirqs last disabled at (0): [<00000000>] 0x0
CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74
Hardware name: Atmel SAMA5
Workqueue: hci0 hci_power_on [bluetooth]
Call trace:
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x44/0x70
dump_stack_lvl from __might_resched+0x38c/0x598
__might_resched from disable_irq+0x1c/0x48
disable_irq from mctrl_gpio_disable_ms+0x74/0xc0
mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4
atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8
atmel_set_termios from uart_change_line_settings+0x15c/0x994
uart_change_line_settings from uart_set_termios+0x2b0/0x668
uart_set_termios from tty_set_termios+0x600/0x8ec
tty_set_termios from ttyport_set_flow_control+0x188/0x1e0
ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc]
wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth]
hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth]
hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth]
hci_power_on [bluetooth] from process_one_work+0x998/0x1a38
process_one_work from worker_thread+0x6e0/0xfb4
worker_thread from kthread+0x3d4/0x484
kthread from ret_from_fork+0x14/0x28
This warning is emitted when trying to toggle, at the highest level,
some flow control (with serdev_device_set_flow_control) in a device
driver. At the lowest level, the atmel_serial driver is using
serial_mctrl_gpio lib to enable/disable the corresponding IRQs
accordingly. The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to
disable_irq (called in mctrl_gpio_disable_ms) being possibly called in
some atomic context (some tty drivers perform modem lines configuration
in regions protected by port lock).
Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one
and a blocking one. Replace mctrl_gpio_disable_ms calls with the
relevant version depending on whether the call is protected by some port
lock.
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Acked-by: Richard Genoud <richard.genoud@bootlin.com>
Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7094832b5a upstream.
The MSM UART DM controller supports different working modes, e.g. DMA or
the "single-character mode", where all reads/writes operate on a single
character rather than 4 chars (32-bit) at once. When using earlycon,
__msm_console_write() always writes 4 characters at a time, but we don't
know which mode the bootloader was using and we don't set the mode either.
This causes garbled output if the bootloader was using the single-character
mode, because only every 4th character appears in the serial console, e.g.
"[ 00oni pi 000xf0[ 00i s 5rm9(l)l s 1 1 SPMTA 7:C 5[ 00A ade k d[
00ano:ameoi .Q1B[ 00ac _idaM00080oo'"
If the bootloader was using the DMA ("DM") mode, output would likely fail
entirely. Later, when the full serial driver probes, the port is
re-initialized and output works as expected.
Fix this also for earlycon by clearing the DMEN register and
reset+re-enable the transmitter to apply the change. This ensures the
transmitter is in the expected state before writing any output.
Cc: stable <stable@kernel.org>
Fixes: 0efe729634 ("tty: serial: msm: Add earlycon support")
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9e512eaaf8 upstream.
When flushing the serial port's buffer, uart_flush_buffer() calls
kfifo_reset() but if there is an outstanding DMA transfer then the
completion function will consume data from the kfifo via
uart_xmit_advance(), underflowing and leading to ongoing DMA as the
driver tries to transmit another 2^32 bytes.
This is readily reproduced with serial-generic and amidi sending even
short messages as closing the device on exit will wait for the fifo to
drain and in the underflow case amidi hangs for 30 seconds on exit in
tty_wait_until_sent(). A trace of that gives:
kworker/1:1-84 [001] 51.769423: bprint: serial8250_tx_dma: tx_size=3 fifo_len=3
amidi-763 [001] 51.769460: bprint: uart_flush_buffer: resetting fifo
irq/21-fe530000-76 [000] 51.769474: bprint: __dma_tx_complete: tx_size=3
irq/21-fe530000-76 [000] 51.769479: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294967293
irq/21-fe530000-76 [000] 51.781295: bprint: __dma_tx_complete: tx_size=4096
irq/21-fe530000-76 [000] 51.781301: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294963197
irq/21-fe530000-76 [000] 51.793131: bprint: __dma_tx_complete: tx_size=4096
irq/21-fe530000-76 [000] 51.793135: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294959101
irq/21-fe530000-76 [000] 51.804949: bprint: __dma_tx_complete: tx_size=4096
Since the port lock is held in when the kfifo is reset in
uart_flush_buffer() and in __dma_tx_complete(), adding a flush_buffer
hook to adjust the outstanding DMA byte count is sufficient to avoid the
kfifo underflow.
Fixes: 9ee4b83e51 ("serial: 8250: Add support for dmaengine")
Cc: stable <stable@kernel.org>
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b06f388994 upstream.
lockdep detects the following circular locking dependency:
CPU 0 CPU 1
========================== ============================
cdns_uart_isr() printk()
uart_port_lock(port) console_lock()
cdns_uart_console_write()
if (!port->sysrq)
uart_port_lock(port)
uart_handle_break()
port->sysrq = ...
uart_handle_sysrq_char()
printk()
console_lock()
The fixed commit attempts to avoid this situation by only taking the
port lock in cdns_uart_console_write if port->sysrq unset. However, if
(as shown above) cdns_uart_console_write runs before port->sysrq is set,
then it will try to take the port lock anyway. This may result in a
deadlock.
Fix this by splitting sysrq handling into two parts. We use the prepare
helper under the port lock and defer handling until we release the lock.
Fixes: 74ea66d4ca ("tty: xuartps: Improve sysrq handling")
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Cc: stable@vger.kernel.org # c980248179: serial: xilinx_uartps: Use port lock wrappers
Acked-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d91f98be26 ]
After a console has written a record into UART_TX, it uses
wait_for_xmitr() to wait until the data has been sent out before
returning. However, wait_for_xmitr() will timeout after 10ms,
regardless if the data has been transmitted or not.
For single bytes, this timeout is sufficient even at very slow
baud rates, such as 1200bps. However, when FIFO mode is used,
there may be 64 bytes pushed into the FIFO at once. At a baud
rate of 115200bps, the 10ms timeout is still sufficient. But
when using lower baud rates (such as 57600bps), the timeout
is _not_ sufficient. This causes longer lines to be cut off,
resulting in lost and horribly misformatted output on the
console.
When using FIFO mode, take the number of bytes into account to
determine an appropriate maximum timeout. Increasing the timeout
does not affect performance since ideally the timeout never
occurs.
Fixes: 8f3631f0f6 ("serial/8250: Use fifo in 8250 console driver")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250107212702.169493-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b5a23a60e8 upstream.
When CONFIG_DMA_ENGINE is disabled, the driver now fails to build:
drivers/tty/serial/amba-pl011.c: In function 'pl011_unthrottle_rx':
drivers/tty/serial/amba-pl011.c:1822:16: error: 'struct uart_amba_port' has no member named 'using_rx_dma'
1822 | if (uap->using_rx_dma) {
| ^~
drivers/tty/serial/amba-pl011.c:1823:20: error: 'struct uart_amba_port' has no member named 'dmacr'
1823 | uap->dmacr |= UART011_RXDMAE;
| ^~
drivers/tty/serial/amba-pl011.c:1824:32: error: 'struct uart_amba_port' has no member named 'dmacr'
1824 | pl011_write(uap->dmacr, uap, REG_DMACR);
| ^~
Add the missing #ifdef check around these field accesses, matching
what other parts of this driver do.
Fixes: 2bcacc1c87 ("serial: amba-pl011: Fix RX stall when DMA is used")
Cc: stable <stable@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202411140617.nkjeHhsK-lkp@intel.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20241115110021.744332-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2bcacc1c87 ]
Function pl011_throttle_rx() calls pl011_stop_rx() to disable RX, which
also disables the RX DMA by clearing the RXDMAE bit of the DMACR
register. However, to properly unthrottle RX when DMA is used, the
function pl011_unthrottle_rx() is expected to set the RXDMAE bit of
the DMACR register, which it currently lacks. This causes RX to stall
after the throttle API is called.
Set RXDMAE bit in the DMACR register while unthrottling RX if RX DMA is
used.
Fixes: 211565b100 ("serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle")
Cc: stable@vger.kernel.org
Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241113092629.60226-1-kkartik@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 68ca3e72d7 ]
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-18-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 2bcacc1c87 ("serial: amba-pl011: Fix RX stall when DMA is used")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bcc7ba6688 upstream.
Currently in omap_8250_shutdown, the dma->rx_running flag is
set to zero in omap_8250_rx_dma_flush. Next pm_runtime_get_sync
is called, which is a runtime resume call stack which can
re-set the flag. When the call omap_8250_shutdown returns, the
flag is expected to be UN-SET, but this is not the case. This
is causing issues the next time UART is re-opened and
omap_8250_rx_dma is called. Fix by moving pm_runtime_get_sync
before the omap_8250_rx_dma_flush.
cc: stable@vger.kernel.org
Fixes: 0e31c8d173 ("tty: serial: 8250_omap: add custom DMA-RX callback")
Signed-off-by: Bin Liu <b-liu@ti.com>
[Judith: Add commit message]
Signed-off-by: Judith Mendez <jm@ti.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20241031172315.453750-1-jm@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3791ea69a4 upstream.
The early_console_setup() function initializes the sci_ports[0].port with
an object of type struct uart_port obtained from the object of type
struct earlycon_device received as argument by the early_console_setup().
It may happen that later, when the rest of the serial ports are probed,
the serial port that was used as earlycon (e.g., port A) to be mapped to a
different position in sci_ports[] and the slot 0 to be used by a different
serial port (e.g., port B), as follows:
sci_ports[0] = port A
sci_ports[X] = port B
In this case, the new port mapped at index zero will have associated data
that was used for earlycon.
In case this happens, after Linux boot, any access to the serial port that
maps on sci_ports[0] (port A) will block the serial port that was used as
earlycon (port B).
To fix this, add early_console_exit() that clean the sci_ports[0] at
earlycon exit time.
Fixes: 0b0cced19a ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7d3b793faa ]
When enabling access to the special register set, Receiver time-out and
RHR interrupts can happen. In this case, the IRQ handler will try to read
from the FIFO thru the RHR register at address 0x00, but address 0x00 is
mapped to DLL register, resulting in erroneous FIFO reading.
Call graph example:
sc16is7xx_startup(): entry
sc16is7xx_ms_proc(): entry
sc16is7xx_set_termios(): entry
sc16is7xx_set_baud(): DLH/DLL = $009C --> access special register set
sc16is7xx_port_irq() entry --> IIR is 0x0C
sc16is7xx_handle_rx() entry
sc16is7xx_fifo_read(): --> unable to access FIFO (RHR) because it is
mapped to DLL (LCR=LCR_CONF_MODE_A)
sc16is7xx_set_baud(): exit --> Restore access to general register set
Fix the problem by claiming the efr_lock mutex when accessing the Special
register set.
Fixes: dfeae619d7 ("serial: sc16is7xx")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240723125302.1305372-3-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Resolve minor conflicts ]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 602babaa84 ]
Commit af224ca2df (serial: core: Prevent unsafe uart port access, part
3) added few uport == NULL checks. It added one to uart_shutdown(), so
the commit assumes, uport can be NULL in there. But right after that
protection, there is an unprotected "uart_port_dtr_rts(uport, false);"
call. That is invoked only if HUPCL is set, so I assume that is the
reason why we do not see lots of these reports.
Or it cannot be NULL at this point at all for some reason :P.
Until the above is investigated, stay on the safe side and move this
dereference to the if too.
I got this inconsistency from Coverity under CID 1585130. Thanks.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240805102046.307511-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Adapted over commit 5701cb8bf5 ("tty: Call ->dtr_rts() parameter
active consistently") not in the tree]
Signed-off-by: Tomas Krcka <krckatom@amazon.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 40d7903386 ]
When sending data using DMA at high baudrate (4 Mbdps in local test case) to
a device with small RX buffer which keeps asserting RTS after every received
byte, it is possible that the iMX UART driver would not recognize the falling
edge of RTS input signal and get stuck, unable to transmit any more data.
This condition happens when the following sequence of events occur:
- imx_uart_mctrl_check() is called at some point and takes a snapshot of UART
control signal status into sport->old_status using imx_uart_get_hwmctrl().
The RTSS/TIOCM_CTS bit is of interest here (*).
- DMA transfer occurs, the remote device asserts RTS signal after each byte.
The i.MX UART driver recognizes each such RTS signal change, raises an
interrupt with USR1 register RTSD bit set, which leads to invocation of
__imx_uart_rtsint(), which calls uart_handle_cts_change().
- If the RTS signal is deasserted, uart_handle_cts_change() clears
port->hw_stopped and unblocks the port for further data transfers.
- If the RTS is asserted, uart_handle_cts_change() sets port->hw_stopped
and blocks the port for further data transfers. This may occur as the
last interrupt of a transfer, which means port->hw_stopped remains set
and the port remains blocked (**).
- Any further data transfer attempts will trigger imx_uart_mctrl_check(),
which will read current status of UART control signals by calling
imx_uart_get_hwmctrl() (***) and compare it with sport->old_status .
- If current status differs from sport->old_status for RTS signal,
uart_handle_cts_change() is called and possibly unblocks the port
by clearing port->hw_stopped .
- If current status does not differ from sport->old_status for RTS
signal, no action occurs. This may occur in case prior snapshot (*)
was taken before any transfer so the RTS is deasserted, current
snapshot (***) was taken after a transfer and therefore RTS is
deasserted again, which means current status and sport->old_status
are identical. In case (**) triggered when RTS got asserted, and
made port->hw_stopped set, the port->hw_stopped will remain set
because no change on RTS line is recognized by this driver and
uart_handle_cts_change() is not called from here to unblock the
port->hw_stopped.
Update sport->old_status in __imx_uart_rtsint() accordingly to make
imx_uart_mctrl_check() detect such RTS change. Note that TIOCM_CAR
and TIOCM_RI bits in sport->old_status do not suffer from this problem.
Fixes: ceca629e0b ("[ARM] 2971/1: i.MX uart handle rts irq")
Cc: stable <stable@kernel.org>
Reviewed-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20241002184133.19427-1-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f16dd10ba3 upstream.
The write to RP2_GLOBAL_CMD followed by an immediate read of
RP2_GLOBAL_CMD in rp2_reset_asic() is intented to flush out the write,
however by then the device is already in reset and cannot respond to a
memory cycle access.
On platforms such as the Raspberry Pi 4 and others using the
pcie-brcmstb.c driver, any memory access to a device that cannot respond
is met with a fatal system error, rather than being substituted with all
1s as is usually the case on PC platforms.
Swapping the delay and the read ensures that the device has finished
resetting before we attempt to read from it.
Fixes: 7d9f49afa4 ("serial: rp2: New driver for Comtrol RocketPort 2 cards")
Cc: stable <stable@kernel.org>
Suggested-by: Jim Quinlan <james.quinlan@broadcom.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240906225435.707837-1-florian.fainelli@broadcom.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c9f6613b16 upstream.
In RS485 mode, the RTS pin is driven high by hardware when the transmitter
is operating. This behaviour cannot be changed. This means that the driver
should claim that it supports SER_RS485_RTS_ON_SEND and not
SER_RS485_RTS_AFTER_SEND.
Otherwise, when configuring the port with the SER_RS485_RTS_ON_SEND, one
get the following warning:
kern.warning kernel: atmel_usart_serial atmel_usart_serial.2.auto:
ttyS1 (1): invalid RTS setting, using RTS_AFTER_SEND instead
which is contradictory with what's really happening.
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Cc: stable <stable@kernel.org>
Tested-by: Alexander Dahl <ada@thorsis.com>
Fixes: af47c491e3 ("serial: atmel: Fill in rs485_supported")
Link: https://lore.kernel.org/r/20240808060637.19886-1-othacehe@gnu.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6eabce6608 upstream.
Calling ioctl TIOCSSERIAL with an invalid baud_base can
result in uartclk being zero, which will result in a
divide by zero error in uart_get_divisor(). The check for
uartclk being zero in uart_set_info() needs to be done
before other settings are made as subsequent calls to
ioctl TIOCSSERIAL for the same port would be impacted if
the uartclk check was done where uartclk gets set.
Oops: divide error: 0000 PREEMPT SMP KASAN PTI
RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580)
Call Trace:
<TASK>
serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576
drivers/tty/serial/8250/8250_port.c:2589)
serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502
drivers/tty/serial/8250/8250_port.c:2741)
serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862)
uart_change_line_settings (./include/linux/spinlock.h:376
./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222)
uart_port_startup (drivers/tty/serial/serial_core.c:342)
uart_startup (drivers/tty/serial/serial_core.c:368)
uart_set_info (drivers/tty/serial/serial_core.c:1034)
uart_set_info_user (drivers/tty/serial/serial_core.c:1059)
tty_set_serial (drivers/tty/tty_io.c:2637)
tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791)
__x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907
fs/ioctl.c:893 fs/ioctl.c:893)
do_syscall_64 (arch/x86/entry/common.c:52
(discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Reported-by: syzkaller <syzkaller@googlegroups.com>
Cc: stable@vger.kernel.org
Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Rule: add
Link: https://lore.kernel.org/stable/1721148848-9784-1-git-send-email-george.kennedy%40oracle.com
Link: https://lore.kernel.org/r/1721219078-3209-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a3d8728ab0 ]
At the default TX trigger level of 2 in non-DMA mode (meaning that an
interrupt is generated when less than 2 characters are left in the
FIFO), we have observed frequent buffer underruns at 115200 Baud on an
i.MX8M Nano. This can cause communication issues if the receiving side
expects a continuous transfer.
Increasing the level to 8 makes the UART trigger an interrupt earlier,
giving the kernel enough time to refill the FIFO, at the cost of
triggering one interrupt per ~24 instead of ~30 bytes of transmitted
data (as the i.MX UART has a 32 byte FIFO).
Signed-off-by: Michael Krummsdorf <michael.krummsdorf@tq-group.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20240508133744.35858-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Thomas Fourier
Nicolas Pitre
Fabio Estevam
Jiri Slaby (SUSE)
Jakub Lewalski
Claudiu Beznea
Henry Martin
Geert Uytterhoeven
Alexis Lothoré
Ryo Takakura
Stephan Gerhold
Sherry Sun
John Keeping
Cameron Williams
Jiaqing Zhao
Sean Anderson
John Ogness
Arnd Bergmann
Inochi Amaoto
Kartik Rajput
Thomas Gleixner
Bin Liu
Filip Brozovic
Greg Kroah-Hartman
Nicolas Bouchinet
Hugo Villeneuve
Jeongjun Park
Marek Vasut
Ilpo Järvinen
Longlong Xia
Florian Fainelli
Mathieu Othacehe
George Kennedy
Matthias Schiffer
Udit Kumar