commit 9e512eaaf8f4008c44ede3dfc0fbc9d9c5118583 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 e8486bd50ecf63c9a1e25271f258a8d959f2672f upstream.
The documentation of the __uart_read_properties() states that
->iotype member is always altered after the function call, but
the code doesn't do that in the case when use_defaults == false
and the value of reg-io-width is unsupported. Make sure the code
follows the documentation.
Note, the current users of the uart_read_and_validate_port_properties()
will fail and the change doesn't affect their behaviour, neither
users of uart_read_port_properties() will be affected since the
alteration happens there even in the current code flow.
Fixes: e894b6005dce ("serial: port: Introduce a common helper to read properties")
Cc: stable <stable@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250124161530.398361-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 166ac2bba167d575e7146beaa66093bc7c072f43 upstream.
Currently the ->iotype is always assigned to the UPIO_MEM when
the respective property is not found. However, this will not
support the cases when user wants to have UPIO_PORT to be set
or preserved. Support this scenario by checking ->iobase value
and default the ->iotype respectively.
Fixes: 1117a6fdc7c1 ("serial: 8250_of: Switch to use uart_read_port_properties()")
Fixes: e894b6005dce ("serial: port: Introduce a common helper to read properties")
Cc: stable <stable@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250124161530.398361-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b06f388994500297bb91be60ffaf6825ecfd2afe 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 # c980248179d: 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 d91f98be26510f5f81ec66425bb0306d1ccd571a ]
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>
[ Upstream commit 9722c3b66e21ff08aec570d02a97d331087fd70f ]
The of_property_for_each_u32() macro needs five parameters, two of which
are primarily meant as internal variables for the macro itself (in the
for() clause). Yet these two parameters are used by a few drivers, and this
can be considered misuse or at least bad practice.
Now that the kernel uses C11 to build, these two parameters can be avoided
by declaring them internally, thus changing this pattern:
struct property *prop;
const __be32 *p;
u32 val;
of_property_for_each_u32(np, "xyz", prop, p, val) { ... }
to this:
u32 val;
of_property_for_each_u32(np, "xyz", val) { ... }
However two variables cannot be declared in the for clause even with C11,
so declare one struct that contain the two variables we actually need. As
the variables inside this struct are not meant to be used by users of this
macro, give the struct instance the noticeable name "_it" so it is visible
during code reviews, helping to avoid new code to use it directly.
Most usages are trivially converted as they do not use those two
parameters, as expected. The non-trivial cases are:
- drivers/clk/clk.c, of_clk_get_parent_name(): easily doable anyway
- drivers/clk/clk-si5351.c, si5351_dt_parse(): this is more complex as the
checks had to be replicated in a different way, making code more verbose
and somewhat uglier, but I refrained from a full rework to keep as much
of the original code untouched having no hardware to test my changes
All the changes have been build tested. The few for which I have the
hardware have been runtime-tested too.
Reviewed-by: Andre Przywara <andre.przywara@arm.com> # drivers/clk/sunxi/clk-simple-gates.c, drivers/clk/sunxi/clk-sun8i-bus-gates.c
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # drivers/gpio/gpio-brcmstb.c
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> # drivers/irqchip/irq-atmel-aic-common.c
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # drivers/iio/adc/ti_am335x_adc.c
Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> # drivers/pwm/pwm-samsung.c
Acked-by: Richard Leitner <richard.leitner@linux.dev> # drivers/usb/misc/usb251xb.c
Acked-by: Mark Brown <broonie@kernel.org> # sound/soc/codecs/arizona.c
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> # sound/soc/codecs/arizona.c
Acked-by: Michael Ellerman <mpe@ellerman.id.au> # arch/powerpc/sysdev/xive/spapr.c
Acked-by: Stephen Boyd <sboyd@kernel.org> # clk
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20240724-of_property_for_each_u32-v3-1-bea82ce429e2@bootlin.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Stable-dep-of: 28fa3291cad1 ("clk: fix an OF node reference leak in of_clk_get_parent_name()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ed2761958ad77e54791802b07095786150eab844 upstream.
The commit f9b11229b7 ("serial: 8250: Fix PM usage_count for console
handover") fixed one runtime PM usage counter balance problem that
occurs because .dev is not set during univ8250 setup preventing call to
pm_runtime_get_sync(). Later, univ8250_console_exit() will trigger the
runtime PM usage counter underflow as .dev is already set at that time.
Call pm_runtime_get_sync() to balance the RPM usage counter also in
serial8250_register_8250_port() before trying to add the port.
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Fixes: bedb404e91 ("serial: 8250_port: Don't use power management for kernel console")
Cc: stable <stable@kernel.org>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20241210170120.2231-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5a23a60e8ab5711f4952912424347bf3864ce8d 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: 2bcacc1c87ac ("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 2bcacc1c87acf9a8ebc17de18cb2b3cfeca547cf ]
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 68ca3e72d7463d79d29b6e4961d6028df2a88e25 ]
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: 2bcacc1c87ac ("serial: amba-pl011: Fix RX stall when DMA is used")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bcc7ba668818dcadd2f1db66b39ed860a63ecf97 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 718632467d88e98816fa01ab12681ef1c2aa56f8 upstream.
This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312.
It was reported to cause boot-time issues, so revert it for now.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit")
Cc: stable <stable@kernel.org>
Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3791ea69a4858b81e0277f695ca40f5aae40f312 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>
commit 635a9fca54f4f4148be1ae1c7c6bd37af80f5773 upstream.
Commit 7c0cca7c84 ("tty: ldisc: add sysctl to prevent autoloading of
ldiscs") introduces the tty_ldisc_autoload sysctl with the wrong
proc_handler. .extra1 and .extra2 parameters are set to avoid other values
thant SYSCTL_ZERO or SYSCTL_ONE to be set but proc_dointvec do not uses
them.
This commit fixes this by using proc_dointvec_minmax instead of
proc_dointvec.
Fixes: 7c0cca7c84 ("tty: ldisc: add sysctl to prevent autoloading of ldiscs")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr>
Reviewed-by: Lin Feng <linf@wangsu.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20241112131357.49582-4-nicolas.bouchinet@clip-os.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7d3b793faaab1305994ce568b59d61927235f57b ]
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>
commit fa103d2599e11e802c818684cff821baefe7f206 upstream.
The receiver is supposed to be enabled in the startup() callback and not
in set_termios() which is called also during console setup.
This specifically avoids accepting input before the port has been opened
(and interrupts enabled), something which can also break the GENI
firmware (cancel fails and after abort, the "stale" counter handling
appears to be broken so that later input is not processed until twelve
chars have been received).
There also does not appear to be any need to keep the receiver disabled
while updating the port settings.
Since commit 6f3c3cafb115 ("serial: qcom-geni: disable interrupts during
console writes") the calls to manipulate the secondary interrupts, which
were done without holding the port lock, can also lead to the receiver
being left disabled when set_termios() races with the console code (e.g.
when init opens the tty during boot). This can manifest itself as a
serial getty not accepting input.
The calls to stop and start rx in set_termios() can similarly race with
DMA completion and, for example, cause the DMA buffer to be unmapped
twice or the mapping to be leaked.
Fix this by only enabling the receiver during startup and while holding
the port lock to avoid racing with the console code.
Fixes: 6f3c3cafb115 ("serial: qcom-geni: disable interrupts during console writes")
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Cc: stable@vger.kernel.org # 6.3
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20241009145110.16847-6-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 23ee4a25661c33e6381d41e848a9060ed6d72845 upstream.
Make sure to wait for the DMA transfer to complete when cancelling the
rx command on stop_rx(). This specifically prevents the DMA completion
interrupt from firing after rx has been restarted, something which can
lead to an IOMMU fault and hosed rx when the interrupt handler unmaps
the DMA buffer for the new command:
qcom_geni_serial 988000.serial: serial engine reports 0 RX bytes in!
arm-smmu 15000000.iommu: FSR = 00000402 [Format=2 TF], SID=0x563
arm-smmu 15000000.iommu: FSYNR0 = 00210013 [S1CBNDX=33 WNR PLVL=3]
Bluetooth: hci0: command 0xfc00 tx timeout
Bluetooth: hci0: Reading QCA version information failed (-110)
Also add the missing state machine reset which is needed in case
cancellation fails.
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Cc: stable@vger.kernel.org # 6.3
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20241009145110.16847-5-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 19df76662a33d2f2fc41a66607cb8285fc02d6ec upstream.
This reverts commit 35781d8356.
Hibernation is not supported on Qualcomm platforms with mainline
kernels yet a broken vendor implementation for the GENI serial driver
made it upstream.
This is effectively dead code that cannot be tested and should just be
removed, but if these paths were ever hit for an open non-console port
they would crash the machine as the driver would fail to enable clocks
during restore() (i.e. all ports would have to be closed by drivers and
user space before hibernating the system to avoid this as a comment in
the code hinted at).
The broken implementation also added a random call to enable the
receiver in the port setup code where it does not belong and which
enables the receiver prematurely for console ports.
Fixes: 35781d8356 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature")
Cc: stable@vger.kernel.org # 6.2
Cc: Aniket Randive <quic_arandive@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20241009145110.16847-3-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 40d7903386df4d18f04d90510ba90eedee260085 upstream.
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>
[ Upstream commit 602babaa84d627923713acaf5f7e9a4369e77473 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 788aeef392d27545ae99af2875068a9dd0531d5f ]
Check if port type is not PORT_UNKNOWN during poll_init.
The kgdboc calls the tty_find_polling_driver that check
if the serial is able to use poll_init. The poll_init calls
the uart uart_poll_init that try to configure the uart with the
selected boot parameters. The uart must be ready before setting
parameters. Seems that PORT_UNKNOWN is already used by other
functions in serial_core to detect uart status, so use the same
to avoid to use it in invalid state.
The crash happen for instance in am62x architecture where the 8250
register the platform driver after the 8250 core is initialized.
Follow the report crash coming from KGDB
Thread 2 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
_outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
584 __raw_writeb(value, PCI_IOBASE + addr);
(gdb) bt
This section of the code is too early because in this case
the omap serial is not probed
Thread 2 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
_outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
584 __raw_writeb(value, PCI_IOBASE + addr);
(gdb) bt
Thread 2 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
_outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
584 __raw_writeb(value, PCI_IOBASE + addr);
(gdb) bt
0 _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
1 logic_outb (value=0 '\000', addr=18446739675637874689) at lib/logic_pio.c:299
2 0xffff80008082dfcc in io_serial_out (p=0x0, offset=16760830, value=0) at drivers/tty/serial/8250/8250_port.c:416
3 0xffff80008082fe34 in serial_port_out (value=<optimized out>, offset=<optimized out>, up=<optimized out>)
at ./include/linux/serial_core.h:677
4 serial8250_do_set_termios (port=0xffff8000828ee940 <serial8250_ports+1568>, termios=0xffff80008292b93c, old=0x0)
at drivers/tty/serial/8250/8250_port.c:2860
5 0xffff800080830064 in serial8250_set_termios (port=0xfffffbfffe800000, termios=0xffbffe, old=0x0)
at drivers/tty/serial/8250/8250_port.c:2912
6 0xffff80008082571c in uart_set_options (port=0xffff8000828ee940 <serial8250_ports+1568>, co=0x0, baud=115200, parity=110, bits=8, flow=110)
at drivers/tty/serial/serial_core.c:2285
7 0xffff800080828434 in uart_poll_init (driver=0xfffffbfffe800000, line=16760830, options=0xffff8000828f7506 <config+6> "115200n8")
at drivers/tty/serial/serial_core.c:2656
8 0xffff800080801690 in tty_find_polling_driver (name=0xffff8000828f7500 <config> "ttyS2,115200n8", line=0xffff80008292ba90)
at drivers/tty/tty_io.c:410
9 0xffff80008086c0b0 in configure_kgdboc () at drivers/tty/serial/kgdboc.c:194
10 0xffff80008086c1ec in kgdboc_probe (pdev=0xfffffbfffe800000) at drivers/tty/serial/kgdboc.c:249
11 0xffff8000808b399c in platform_probe (_dev=0xffff000000ebb810) at drivers/base/platform.c:1404
12 0xffff8000808b0b44 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:579
13 really_probe (dev=0xffff000000ebb810, drv=0xffff80008277f138 <kgdboc_platform_driver+48>) at drivers/base/dd.c:658
14 0xffff8000808b0d2c in __driver_probe_device (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, dev=0xffff000000ebb810)
at drivers/base/dd.c:800
15 0xffff8000808b0eb8 in driver_probe_device (drv=0xfffffbfffe800000, dev=0xffff000000ebb810) at drivers/base/dd.c:830
16 0xffff8000808b0ff4 in __device_attach_driver (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, _data=0xffff80008292bc48)
at drivers/base/dd.c:958
17 0xffff8000808ae970 in bus_for_each_drv (bus=0xfffffbfffe800000, start=0x0, data=0xffff80008292bc48,
fn=0xffff8000808b0f3c <__device_attach_driver>) at drivers/base/bus.c:457
18 0xffff8000808b1408 in __device_attach (dev=0xffff000000ebb810, allow_async=true) at drivers/base/dd.c:1030
19 0xffff8000808b16d8 in device_initial_probe (dev=0xfffffbfffe800000) at drivers/base/dd.c:1079
20 0xffff8000808af9f4 in bus_probe_device (dev=0xffff000000ebb810) at drivers/base/bus.c:532
21 0xffff8000808ac77c in device_add (dev=0xfffffbfffe800000) at drivers/base/core.c:3625
22 0xffff8000808b3428 in platform_device_add (pdev=0xffff000000ebb800) at drivers/base/platform.c:716
23 0xffff800081b5dc0c in init_kgdboc () at drivers/tty/serial/kgdboc.c:292
24 0xffff800080014db0 in do_one_initcall (fn=0xffff800081b5dba4 <init_kgdboc>) at init/main.c:1236
25 0xffff800081b0114c in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1298
26 do_initcalls () at init/main.c:1314
27 do_basic_setup () at init/main.c:1333
28 kernel_init_freeable () at init/main.c:1551
29 0xffff8000810271ec in kernel_init (unused=0xfffffbfffe800000) at init/main.c:1441
30 0xffff800080015e80 in ret_from_fork () at arch/arm64/kernel/entry.S:857
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Link: https://lore.kernel.org/r/20231224131200.266224-1-michael@amarulasolutions.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: d0009a32c9e4 ("serial: don't use uninitialized value in uart_poll_init()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c80ee36ac8f9e9c27d8e097a2eaaf198e7534c83 upstream.
The qcom_geni_serial_poll_bit() can be used to wait for events like
command completion and is supposed to wait for the time it takes to
clear a full fifo before timing out.
As noted by Doug, the current implementation does not account for start,
stop and parity bits when determining the timeout. The helper also does
not currently account for the shift register and the two-word
intermediate transfer register.
A too short timeout can specifically lead to lost characters when
waiting for a transfer to complete as the transfer is cancelled on
timeout.
Instead of determining the poll timeout on every call, store the fifo
timeout when updating it in set_termios() and make sure to take the
shift and intermediate registers into account. Note that serial core has
already added a 20 ms margin to the fifo timeout.
Also note that the current uart_fifo_timeout() interface does
unnecessary calculations on every call and did not exist in earlier
kernels so only store its result once. This facilitates backports too as
earlier kernels can derive the timeout from uport->timeout, which has
since been removed.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Cc: stable@vger.kernel.org # 4.17
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240906131336.23625-2-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f16dd10ba342c429b1e36ada545fb36d4d1f0e63 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 c9f6613b16123989f2c3bd04b1d9b2365d6914e7 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 dc98d76a15bc29a9a4e76f2f65f39f3e590fb15c upstream.
With "earlycon initcall_debug=1 loglevel=8" in bootargs, kernel
sometimes boot hang. It is because normal console still is not ready,
but runtime suspend is called, so early console putchar will hang
in waiting TRDE set in UARTSTAT.
The lpuart driver has auto suspend delay set to 3000ms, but during
uart_add_one_port, a child device serial ctrl will added and probed with
its pm runtime enabled(see serial_ctrl.c).
The runtime suspend call path is:
device_add
|-> bus_probe_device
|->device_initial_probe
|->__device_attach
|-> pm_runtime_get_sync(dev->parent);
|-> pm_request_idle(dev);
|-> pm_runtime_put(dev->parent);
So in the end, before normal console ready, the lpuart get runtime
suspended. And earlycon putchar will hang.
To address the issue, mark last busy just after pm_runtime_enable,
three seconds is long enough to switch from bootconsole to normal
console.
Fixes: 43543e6f53 ("tty: serial: fsl_lpuart: Add runtime pm support")
Cc: stable <stable@kernel.org>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20240808140325.580105-1-peng.fan@oss.nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6eabce6608d6f3440f4c03aa3d3ef50a47a3d193 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 a3d8728ab079951741efa11360df43dbfacba7ab ]
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>
commit 9706fc87b4cff0ac4f5d5d62327be83fe72e3108 upstream.
With commit a81dbd0463ec ("serial: imx: set receiver level before
starting uart") we set the receiver level to its default value. This
caused a regression when using SDMA, where the receiver level is 9
instead of 8 (default). This change will first check if the receiver
level is zero and only then set it to the default. This still avoids the
interrupt storm when the receiver level is zero.
Fixes: a81dbd0463ec ("serial: imx: set receiver level before starting uart")
Cc: stable <stable@kernel.org>
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Link: https://lore.kernel.org/r/20240703112543.148304-1-eichest@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ea55c65dedf40e9c1911dc1e63e26bc9a59692b9 upstream.
When bcm63xx-uart was converted to uart_port_tx_limited(), it implicitly
added a call to stop_tx(). This causes garbage to be put out on the
serial console. To fix this, pass UART_TX_NOSTOP in flags, and manually
call stop_tx() ourselves analogue to how a similar issue was fixed in
commit 7be50f2e8f20 ("serial: mxs-auart: fix tx").
Fixes: d11cc8c3c4 ("tty: serial: use uart_port_tx_limited()")
Cc: stable@vger.kernel.org
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Doug Brown <doug@schmorgal.com>
Link: https://lore.kernel.org/r/20240606195632.173255-4-doug@schmorgal.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a81dbd0463eca317eee44985a66aa6cc2ce5c101 upstream.
Set the receiver level to something > 0 before calling imx_uart_start_rx
in rs485_config. This is necessary to avoid an interrupt storm that
might prevent the system from booting. This was seen on an i.MX7 device
when the rs485-rts-active-low property was active in the device tree.
Fixes: 6d215f83e5 ("serial: imx: warn user when using unsupported configuration")
Cc: stable <stable@kernel.org>
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Link: https://lore.kernel.org/r/20240621153829.183780-1-eichest@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2c94512055f362dd789e0f87b8566feeddec83c9 upstream.
This reverts commit d9666dfb31.
The container of the struct dw8250_port_data is private to the actual
driver. In particular, 8250_lpss and 8250_dw use different data types
that are assigned to the UART port private_data. Hence, it must not
be used outside the specific driver.
Fix the mistake made in the past by moving the respective definitions
to the specific driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240514190730.2787071-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 87d80bfbd577912462061b1a45c0ed9c7fcb872f ]
The container of the struct dw8250_port_data is private to the actual
driver. In particular, 8250_lpss and 8250_dw use different data types
that are assigned to the UART port private_data. Hence, it must not
be used outside the specific driver.
Currently the only cpr_val is required by the common code, make it
be available via struct dw8250_port_data.
This fixes the UART breakage on Intel Galileo boards.
Fixes: 593dea000b ("serial: 8250: dw: Allow to use a fallback CPR value if not synthesized")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240514190730.2787071-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
