commit 637674fa40059cddcc3ad2212728965072f62ea3 upstream.
The EndRun PTP/1588 dual serial port device is based on the Oxford
Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set
for EndRun Technologies and is therefore driven by a fixed 62.5MHz clock
input derived from the 100MHz PCI Express clock. The clock rate is
divided by the oversampling rate of 16 as it is supplied to the baud
rate generator, yielding the baud base of 3906250.
Replace the incorrect baud base of 4000000 with the right value of
3906250 then, complementing commit 6cbe45d8ac ("serial: 8250: Correct
the clock for OxSemi PCIe devices").
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable <stable@kernel.org>
Fixes: 1bc8cde46a ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6e6eebdf5e2455f089ccd000754a0deaeb79af82 upstream.
Sticky MCR bits are lost in console restoration if console suspending
has been disabled. This currently affects the AFE bit, which works in
combination with RTS which we set, so we want to make sure the UART
retains control of its FIFO where previously requested. Also specific
drivers may need other bits in the future.
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 4516d50aab ("serial: 8250: Use canary to restart console after suspend")
Cc: stable@vger.kernel.org # v4.0+
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0e4deb56b0c625efdb70c94f150429e2f2a16fa1 upstream.
The current timeout for draining the tx fifo in RS485 mode is calculated by
multiplying the time it takes to transmit one character (with the given
baud rate) with the maximal number of characters in the tx queue.
This timeout is too short for two reasons:
First when calculating the time to transmit one character integer division
is used which may round down the result in case of a remainder of the
division.
Fix this by rounding up the division result.
Second the hardware may need additional time (e.g for first putting the
characters from the fifo into the shift register) before the characters are
actually put onto the wire.
To be on the safe side double the current maximum number of iterations
that are used to wait for the queue draining.
Fixes: 8d47923772 ("serial: amba-pl011: add RS485 support")
Cc: stable@vger.kernel.org
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Link: https://lore.kernel.org/r/20220408233503.7251-1-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ee82c6e41f3d2212647ce0bc5a05a0f69097824 upstream.
Commit 76821e222c ("serial: imx: ensure that RX irqs are off if RX is
off") accidentally enabled overrun interrupts unconditionally when
deferring DMA enable until after the receiver has been enabled during
startup.
Fix this by using the DMA-initialised instead of DMA-enabled flag to
determine whether overrun interrupts should be enabled.
Note that overrun interrupts are already accounted for in
imx_uart_clear_rx_errors() when using DMA since commit 41d98b5da9
("serial: imx-serial - update RX error counters when DMA is used").
Fixes: 76821e222c ("serial: imx: ensure that RX irqs are off if RX is off")
Cc: stable@vger.kernel.org # 4.17
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220411081957.7846-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 988c7c00691008ea1daaa1235680a0da49dab4e8 ]
The commit c15c3747ee (serial: samsung: fix potential soft lockup
during uart write) added an unlock of port->lock before
uart_write_wakeup() and a lock after it. It was always problematic to
write data from tty_ldisc_ops::write_wakeup and it was even documented
that way. We fixed the line disciplines to conform to this recently.
So if there is still a missed one, we should fix them instead of this
workaround.
On the top of that, s3c24xx_serial_tx_dma_complete() in this driver
still holds the port->lock while calling uart_write_wakeup().
So revert the wrap added by the commit above.
Cc: Thomas Abraham <thomas.abraham@linaro.org>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Hyeonkook Kim <hk619.kim@samsung.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220308115153.4225-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f58c252e30cf74f68b0054293adc03b5923b9f0e ]
When 8250 UART is using DMA, x_char (XON/XOFF) is never sent
to the wire. After this change, x_char is injected correctly.
Create uart_xchar_out() helper for sending the x_char out and
accounting related to it. It seems that almost every driver
does these same steps with x_char. Except for 8250, however,
almost all currently lack .serial_out so they cannot immediately
take advantage of this new helper.
The downside of this patch is that it might reintroduce
the problems some devices faced with mixed DMA/non-DMA transfer
which caused revert f967fc8f16 (Revert "serial: 8250_dma:
don't bother DMA with small transfers"). However, the impact
should be limited to cases with XON/XOFF (that didn't work
with DMA capable devices to begin with so this problem is not
very likely to cause a major issue, if any at all).
Fixes: 9ee4b83e51 ("serial: 8250: Add support for dmaengine")
Reported-by: Gilles Buloz <gilles.buloz@kontron.com>
Tested-by: Gilles Buloz <gilles.buloz@kontron.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dedab69fd650ea74710b2e626e63fd35584ef773 ]
Set em485->active_timer = NULL isn't always enough to take out the stop
timer. While there is a check that it acts in the right state (i.e.
waiting for RTS-after-send to pass after sending some chars) but the
following might happen:
- CPU1: some chars send, shifter becomes empty, stop tx timer armed
- CPU0: more chars send before RTS-after-send expired
- CPU0: shifter empty irq, port lock taken
- CPU1: tx timer triggers, waits for port lock
- CPU0: em485->active_timer = &em485->stop_tx_timer, hrtimer_start(),
releases lock()
- CPU1: get lock, see em485->active_timer == &em485->stop_tx_timer,
tear down RTS too early
This fix bases on research done by Steffen Trumtrar.
Fixes: b86f86e8e7 ("serial: 8250: fix potential deadlock in rs485-mode")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220215160236.344236-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a603ca60cebff8589882427a67f870ed946b3fc8 ]
Commit 54da3e381c ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to
set up register mapping") fixed a bug that had, as a side-effect,
prevented the 8250_aspeed_vuart driver from enabling the VUART's
FIFOs. However, fixing that (and hence enabling the FIFOs) has in
turn revealed what appears to be a hardware bug in the ASPEED VUART in
which the host-side THRE bit doesn't get if the BMC-side receive FIFO
trigger level is set to anything but one byte. This causes problems
for polled-mode writes from the host -- for example, Linux kernel
console writes proceed at a glacial pace (less than 100 bytes per
second) because the write path waits for a 10ms timeout to expire
after every character instead of being able to continue on to the next
character upon seeing THRE asserted. (GRUB behaves similarly.)
As a workaround, introduce a new port type for the ASPEED VUART that's
identical to PORT_16550A as it had previously been using, but with
UART_FCR_R_TRIG_00 instead to set the receive FIFO trigger level to
one byte, which (experimentally) seems to avoid the problematic THRE
behavior.
Fixes: 54da3e381c ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping")
Tested-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20220211004203.14915-1-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d3d079bde07e1b7deaeb57506dc0b86010121d17 ]
When sending x_char in stm32_usart_transmit_chars(), driver can overwrite
the value of TDR register by the value of x_char. If this happens, the
previous value that was present in TDR register will not be sent through
uart.
This code checks if the previous value in TDR register is sent before
writing the x_char value into register.
Fixes: 48a6092fb4 ("serial: stm32-usart: Add STM32 USART Driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220111164441.6178-2-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit eebb0f4e894f1e9577a56b337693d1051dd6ebfd upstream.
UART drivers are meant to use the port spinlock within certain
methods, to protect against reentrancy. The sc16is7xx driver does
very little locking, presumably because when added it triggers
"scheduling while atomic" errors. This is due to the use of mutexes
within the regmap abstraction layer, and the mutex implementation's
habit of sleeping the current thread while waiting for access.
Unfortunately this lack of interlocking can lead to corruption of
outbound data, which occurs when the buffer used for I2C transmission
is used simultaneously by two threads - a work queue thread running
sc16is7xx_tx_proc, and an IRQ thread in sc16is7xx_port_irq, both
of which can call sc16is7xx_handle_tx.
An earlier patch added efr_lock, a mutex that controls access to the
EFR register. This mutex is already claimed in the IRQ handler, and
all that is required is to claim the same mutex in sc16is7xx_tx_proc.
See: https://github.com/raspberrypi/linux/issues/4885
Fixes: 6393ff1c44 ("sc16is7xx: Use threaded IRQ")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Link: https://lore.kernel.org/r/20220216160802.1026013-1-phil@raspberrypi.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6e8793674bb0d1135ca0e5c9f7e16fecbf815926 upstream.
There is a build error when using a kernel .config file from
'kernel test robot' for a different build problem:
hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3':
(.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq'
when:
CONFIG_GSC=y
CONFIG_SERIO_GSCPS2=y
CONFIG_SERIAL_8250_GSC=y
CONFIG_PCI is not set
and hence PCI_LBA is not set.
IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled.
Make the use of iosapic_serial_irq() conditional to fix the build error.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Suggested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d06b1cf28297e27127d3da54753a3a01a2fa2f28 upstream.
8250_of supports a reg-offset property which is intended to handle
cases where the device registers start at an offset inside the region
of memory allocated to the device. The Xilinx 16550 UART, for which this
support was initially added, requires this. However, the code did not
adjust the overall size of the mapped region accordingly, causing the
driver to request an area of memory past the end of the device's
allocation. For example, if the UART was allocated an address of
0xb0130000, size of 0x10000 and reg-offset of 0x1000 in the device
tree, the region of memory reserved was b0131000-b0140fff, which caused
the driver for the region starting at b0140000 to fail to probe.
Fix this by subtracting reg-offset from the mapped region size.
Fixes: b912b5e2cf ([POWERPC] Xilinx: of_serial support for Xilinx uart 16550.)
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Link: https://lore.kernel.org/r/20220112194214.881844-1-robert.hancock@calian.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d3b3404df318504ec084213ab1065b73f49b0f1d upstream.
Commit a6845e1e1b ("serial: core: Consider rs485 settings to drive
RTS") sought to deassert RTS when opening an rs485-enabled uart port.
That way, the transceiver does not occupy the bus until it transmits
data.
Unfortunately, the commit mixed up the logic and *asserted* RTS instead
of *deasserting* it:
The commit amended uart_port_dtr_rts(), which raises DTR and RTS when
opening an rs232 port. "Raising" actually means lowering the signal
that's coming out of the uart, because an rs232 transceiver not only
changes a signal's voltage level, it also *inverts* the signal. See
the simplified schematic in the MAX232 datasheet for an example:
https://www.ti.com/lit/ds/symlink/max232.pdf
So, to raise RTS on an rs232 port, TIOCM_RTS is *set* in port->mctrl
and that results in the signal being driven low.
In contrast to rs232, the signal level for rs485 Transmit Enable is the
identity, not the inversion: If the transceiver expects a "high" RTS
signal for Transmit Enable, the signal coming out of the uart must also
be high, so TIOCM_RTS must be *cleared* in port->mctrl.
The commit did the exact opposite, but it's easy to see why given the
confusing semantics of rs232 and rs485. Fix it.
Fixes: a6845e1e1b ("serial: core: Consider rs485 settings to drive RTS")
Cc: stable@vger.kernel.org # v4.14+
Cc: Rafael Gago Castano <rgc@hms.se>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Su Bao Cheng <baocheng.su@siemens.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/9395767847833f2f3193c49cde38501eeb3b5669.1639821059.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 93a770b7e16772530196674ffc79bb13fa927dc6 ]
struct uart_port contains a cached copy of the Modem Control signals.
It is used to skip register writes in uart_update_mctrl() if the new
signal state equals the old signal state. It also avoids a register
read to obtain the current state of output signals.
When a uart_port is registered, uart_configure_port() changes signal
state but neglects to keep the cached copy in sync. That may cause
a subsequent register write to be incorrectly skipped. Fix it before
it trips somebody up.
This behavior has been present ever since the serial core was introduced
in 2002:
https://git.kernel.org/history/history/c/33c0d1b0c3eb
So far it was never an issue because the cached copy is initialized to 0
by kzalloc() and when uart_configure_port() is executed, at most DTR has
been set by uart_set_options() or sunsu_console_setup(). Therefore,
a stable designation seems unnecessary.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/bceeaba030b028ed810272d55d5fc6f3656ddddb.1641129752.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e368cc656fd6d0075f1c3ab9676e2001451e3e04 ]
pl011_set_termios() briefly resets the CR register to zero, thereby
glitching DTR/RTS signals. With rs485 this may result in the bus being
occupied for no reason.
Where does this register write originate from?
The PL011 driver was forked from the PL010 driver in 2004:
https://git.kernel.org/history/history/c/157c0342e591
Until this commit, the PL010 driver's IRQ handler ambauart_int()
modified the CR register without holding the port spinlock.
ambauart_set_termios() also modified that register. To prevent
concurrent read-modify-writes by the IRQ handler and to prevent
transmission while changing baudrate, ambauart_set_termios() had to
disable interrupts. On the PL010, that is achieved by writing zero to
the CR register.
However, on the PL011, interrupts are disabled in the IMSC register,
not in the CR register.
Additionally, the commit amended both the PL010 and PL011 driver to
acquire the port spinlock in the IRQ handler, obviating the need to
disable interrupts in ->set_termios().
So the CR register write is obsolete for two reasons. Drop it.
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/f49f945375f5ccb979893c49f1129f51651ac738.1641129062.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 08a0c6dff91c965e39905cf200d22db989203ccb ]
pl010_set_termios() briefly resets the CR register to zero.
Where does this register write come from?
The PL010 driver's IRQ handler ambauart_int() originally modified the CR
register without holding the port spinlock. ambauart_set_termios() also
modified that register. To prevent concurrent read-modify-writes by the
IRQ handler and to prevent transmission while changing baudrate,
ambauart_set_termios() had to disable interrupts. That is achieved by
writing zero to the CR register.
However in 2004 the PL010 driver was amended to acquire the port
spinlock in the IRQ handler, obviating the need to disable interrupts in
->set_termios():
https://git.kernel.org/history/history/c/157c0342e591
That rendered the CR register write obsolete. Drop it.
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/fcaff16e5b1abb4cc3da5a2879ac13f278b99ed0.1641128728.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 028e083832b06fdeeb290e1e57dc1f6702c4c215 ]
The UCR4_OREN should be disabled before disabling the uart receiver in
.stop_rx() instead of in the .shutdown().
Otherwise, if we have the overrun error during the receiver disable
process, the overrun interrupt will keep trigging until we disable the
OREN interrupt in the .shutdown(), because the ORE status can only be
cleared when read the rx FIFO or reset the controller. Although the
called time between the receiver disable and OREN disable in .shutdown()
is very short, there is still the risk of endless interrupt during this
short period of time. So here change to disable OREN before the receiver
been disabled in .stop_rx().
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20211125020349.4980-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d1180405c7b5c7a1c6bde79d5fc24fe931430737 ]
With commit 3873e2d7f6 ("drivers: PL011: refactor pl011_probe()") the
function devm_ioremap() called from pl011_setup_port() was replaced with
devm_ioremap_resource(). Since this function not only remaps but also
requests the ports io memory region it now collides with the .config_port()
callback which requests the same region at uart port registration.
Since devm_ioremap_resource() already claims the memory successfully, the
request in .config_port() fails.
Later at uart port deregistration the attempt to release the unclaimed
memory also fails. The failure results in a “Trying to free nonexistent
resource" warning.
Fix these issues by removing the callbacks that implement the redundant
memory allocation/release. Also make sure that changing the drivers io
memory base address via TIOCSSERIAL is not allowed any more.
Fixes: 3873e2d7f6 ("drivers: PL011: refactor pl011_probe()")
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Link: https://lore.kernel.org/r/20211129174238.8333-1-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3672fb65155530b5eea6225685c75329b6debec3 ]
The base address of uartlite registers could be 64 bit address which is from
device resource. When ulite_probe() calls ulite_assign(), this 64 bit
address is casted to 32-bit. The fix is to replace "u32" type with
"phys_addr_t" type for the base address in ulite_assign() argument list.
Fixes: 8fa7b61006 ("[POWERPC] Uartlite: Separate the bus binding from the driver proper")
Signed-off-by: Lizhi Hou <lizhi.hou@xilinx.com>
Link: https://lore.kernel.org/r/20211129202302.1319033-1-lizhi.hou@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b ]
The driver wrongly assummed that tx_submit() will start the transfer,
which is not the case, now that the at_xdmac driver is fixed. tx_submit
is supposed to push the current transaction descriptor to a pending queue,
waiting for issue_pending to be called. issue_pending must start the
transfer, not tx_submit.
Fixes: 34df42f59a ("serial: at91: add rx dma support")
Fixes: 08f738be88 ("serial: at91: add tx dma support")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1e67bd2b8cb90b66e89562598e9c2046246832d3 ]
The tx_submit() method of struct dma_async_tx_descriptor is entitled
to do sanity checks and return errors if encountered. It's not the
case for the DMA controller drivers that this client is using
(at_h/xdmac), because they currently don't do sanity checks and always
return a positive cookie at tx_submit() method. In case the controller
drivers will implement sanity checks and return errors, print a message
so that the client will be informed that something went wrong at
tx_submit() level.
Fixes: 08f738be88 ("serial: at91: add tx dma support")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20211125090028.786832-3-tudor.ambarus@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6c33ff728812aa18792afffaf2c9873b898e7512 upstream.
Commit fab8a02b73 ("serial: 8250_fintek: Enable high speed mode on Fintek F81866")
introduced support to use high baudrate with Fintek SuperIO UARTs. It'll
change clocksources when the UART probed.
But when user add kernel parameter "console=ttyS0,115200 console=tty0" to make
the UART as console output, the console will output garbled text after the
following kernel message.
[ 3.681188] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
The issue is occurs in following step:
probe_setup_port() -> fintek_8250_goto_highspeed()
It change clocksource from 115200 to 921600 with wrong time, it should change
clocksource in set_termios() not in probed. The following 3 patches are
implemented change clocksource in fintek_8250_set_termios().
Commit 58178914ae ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81216H")
Commit 195638b6d4 ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81866")
Commit 423d9118c6 ("serial: 8250_fintek: Add F81966 Support")
Due to the high baud rate had implemented above 3 patches and the patch
Commit fab8a02b73 ("serial: 8250_fintek: Enable high speed mode on Fintek F81866")
is bugged, So this patch will remove it.
Fixes: fab8a02b73 ("serial: 8250_fintek: Enable high speed mode on Fintek F81866")
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Link: https://lore.kernel.org/r/20211215075835.2072-1-hpeter+linux_kernel@gmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4e9679738a918d8a482ac6a2cb2bb871f094bb84 ]
Revert commit b4b844930f ("tty: serial: fsl_lpuart: drop earlycon entry
for i.MX8QXP"), because this breaks earlycon support on imx8qm/imx8qxp.
While it is true that for earlycon there is no difference between
i.MX8QXP and i.MX7ULP (for now at least), there are differences
regarding clocks and fixups for wakeup support. For that reason it was
deemed unacceptable to add the imx7ulp compatible to device tree in
order to get earlycon working again.
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20211124073109.805088-1-alexander.stein@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f85e04503f369b3f2be28c83fc48b74e19936ebc upstream.
Commit f45709df77 ("serial: 8250: Don't touch RTS modem control while
in rs485 mode") sought to prevent user space from interfering with rs485
communication by ignoring a TIOCMSET ioctl() which changes RTS polarity.
It did so in serial8250_do_set_mctrl(), which turns out to be too deep
in the call stack: When a uart_port is opened, RTS polarity is set by
the rs485-aware function uart_port_dtr_rts(). It calls down to
serial8250_do_set_mctrl() and that particular RTS polarity change should
*not* be ignored.
The user-visible result is that on 8250_omap ports which use rs485 with
inverse polarity (RTS bit in MCR register is 1 to receive, 0 to send),
a newly opened port initially sets up RTS for sending instead of
receiving. That's because omap_8250_startup() sets the cached value
up->mcr to 0 and omap_8250_restore_regs() subsequently writes it to the
MCR register. Due to the commit, serial8250_do_set_mctrl() preserves
that incorrect register value:
do_sys_openat2
do_filp_open
path_openat
vfs_open
do_dentry_open
chrdev_open
tty_open
uart_open
tty_port_open
uart_port_activate
uart_startup
uart_port_startup
serial8250_startup
omap_8250_startup # up->mcr = 0
uart_change_speed
serial8250_set_termios
omap_8250_set_termios
omap_8250_restore_regs
serial8250_out_MCR # up->mcr written
tty_port_block_til_ready
uart_dtr_rts
uart_port_dtr_rts
serial8250_set_mctrl
omap8250_set_mctrl
serial8250_do_set_mctrl # mcr[1] = 1 ignored
Fix by intercepting RTS changes from user space in uart_tiocmset()
instead.
Link: https://lore.kernel.org/linux-serial/20211027111644.1996921-1-baocheng.su@siemens.com/
Fixes: f45709df77 ("serial: 8250: Don't touch RTS modem control while in rs485 mode")
Cc: Chao Zeng <chao.zeng@siemens.com>
Cc: stable@vger.kernel.org # v5.7+
Reported-by: Su Bao Cheng <baocheng.su@siemens.com>
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Su Bao Cheng <baocheng.su@siemens.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/21170e622a1aaf842a50b32146008b5374b3dd1d.1637596432.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bb1201d4b38ec67bd9a871cf86b0cc10f28b15b5 upstream.
Have pericom_do_set_divisor() use the uartclk instead of a hard coded
value to work with different speed crystals. Tested with 14.7456 and 24
MHz crystals.
Have pericom_do_set_divisor() always calculate the divisor rather than
call serial8250_do_set_divisor() for rates below baud_base.
Do not write registers or call serial8250_do_set_divisor() if valid
divisors could not be found.
Fixes: 6bf4e42f1d ("serial: 8250: Add support for higher baud rates to Pericom chips")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jay Dolan <jay.dolan@accesio.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211122120604.3909-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00de977f9e0aa9760d9a79d1e41ff780f74e3424 upstream.
Commit 761ed4a945 ("tty: serial_core: convert uart_close to use
tty_port_close") converted serial core to use tty_port_close() but
failed to notice that the transmit buffer still needs to be freed on
final close.
Not freeing the transmit buffer means that the buffer is no longer
cleared on next open so that any ioctl() waiting for the buffer to drain
might wait indefinitely (e.g. on termios changes) or that stale data can
end up being transmitted in case tx is restarted.
Furthermore, the buffer of any port that has been opened would leak on
driver unbind.
Note that the port lock is held when clearing the buffer pointer due to
the ldisc race worked around by commit a5ba1d95e4 ("uart: fix race
between uart_put_char() and uart_shutdown()").
Also note that the tty-port shutdown() callback is not called for
console ports so it is not strictly necessary to free the buffer page
after releasing the lock (cf. d72402145a ("tty/serial: do not free
trasnmit buffer page under port lock")).
Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il
Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Cc: stable@vger.kernel.org # 4.9
Cc: Rob Herring <robh@kernel.org>
Reported-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b40de7469ef135161c80af0e8c462298cc5dac00 upstream.
The current implementation uses 0 as lower limit for the baud rate
tolerance for tegra20 and tegra30 chips which causes isses on UART
initialization as soon as baud rate clock is lower than required even
when within the standard UART tolerance of +/- 4%.
This fix aligns the implementation with the initial commit description
of +/- 4% tolerance for tegra chips other than tegra186 and
tegra194.
Fixes: d781ec21ba ("serial: tegra: report clk rate errors")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Patrik John <patrik.john@u-blox.com>
Link: https://lore.kernel.org/r/sig.19614244f8.20211123132737.88341-1-patrik.john@u-blox.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ac442a077acf9a6bf1db4320ec0c3f303be092b3 upstream.
The document 'ACPI for Arm Components 1.0' defines the following
_HID mappings:
-'Prime cell UART (PL011)': ARMH0011
-'SBSA UART': ARMHB000
Use the sbsa-uart driver when a device is described with
the 'ARMHB000' _HID.
Note:
PL011 devices currently use the sbsa-uart driver instead of the
uart-pl011 driver. Indeed, PL011 devices are not bound to a clock
in ACPI. It is not possible to change their baudrate.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Link: https://lore.kernel.org/r/20211109172248.19061-1-Pierre.Gondois@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7492ffc90fa126afb67d4392d56cb4134780194a upstream.
The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of
setup, it is often sharing a serial device with the normal system console.
This is usually no problem because the polling helpers can consume input
values directly (when in kgdb context) and the normal Linux handlers can
only consume new input values after kgdb switched back.
This is not true anymore when RX DMA is enabled for UARTDM controllers.
Single input values can no longer be received correctly. Instead following
seems to happen:
* on 1. input, some old input is read (continuously)
* on 2. input, two old inputs are read (continuously)
* on 3. input, three old input values are read (continuously)
* on 4. input, 4 previous inputs are received
This repeats then for each group of 4 input values.
This behavior changes slightly depending on what state the controller was
when the first input was received. But this makes working with kgdb
basically impossible because control messages are always corrupted when
kgdboc tries to parse them.
RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid
these kind of problems. No such problem was noticed for TX DMA.
Fixes: 9969394501 ("tty: serial: msm: Add RX DMA support")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9cabe26e65a893afd5846908aa393bd283ab6609 ]
There is a small window in time during resume where the hardware
flow control signal RTS can be asserted (which allows a sender to
resume sending data to the UART) but the baud rate has not yet
been restored. This will cause corrupted data and FRAMING, OVERRUN
and BREAK errors. This is happening because the MCTRL register is
shadowed in uart_port struct and is later used during resume to set
the MCTRL register during both serial8250_do_startup() and
uart_resume_port(). Unfortunately, serial8250_do_startup()
happens before the UART baud rate is restored. The fix is to clear
the shadowed mctrl value at the end of suspend and restore it at the
end of resume.
Fixes: 41a469482d ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Link: https://lore.kernel.org/r/20211201201402.47446-1-alcooperx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d142585bceb3218ad432ed0fcd5be9d6e3cd9052 ]
If CONFIG_CONSOLE_POLL=y, and CONFIG_SERIAL_CPM=m (hence
CONFIG_SERIAL_CPM_CONSOLE=n):
drivers/tty/serial/cpm_uart/cpm_uart_core.c:1109:12: warning: ‘udbg_cpm_getc’ defined but not used [-Wunused-function]
1109 | static int udbg_cpm_getc(void)
| ^~~~~~~~~~~~~
drivers/tty/serial/cpm_uart/cpm_uart_core.c:1095:13: warning: ‘udbg_cpm_putc’ defined but not used [-Wunused-function]
1095 | static void udbg_cpm_putc(char c)
| ^~~~~~~~~~~~~
Fix this by making the udbg definitions depend on
CONFIG_SERIAL_CPM_CONSOLE, in addition to CONFIG_CONSOLE_POLL.
Fixes: a60526097f ("tty: serial: cpm_uart: Add udbg support for enabling xmon")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20211027075326.3270785-1-geert@linux-m68k.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 88b20f84f0fe47409342669caf3e58a3fc64c316 ]
xilinx_uartps .start_tx() clears TXEMPTY when enabling TXEMPTY to avoid
any previous TXEVENT event asserting the UART interrupt. This clear
operation is done immediately after filling the TX FIFO.
However, if the bytes inserted by cdns_uart_handle_tx() are consumed by
the UART before the TXEMPTY is cleared, the clear operation eats the new
TXEMPTY event as well, causing cdns_uart_isr() to never receive the
TXEMPTY event. If there are bytes still queued in circbuf, TX will get
stuck as they will never get transferred to FIFO (unless new bytes are
queued to circbuf in which case .start_tx() is called again).
While the racy missed TXEMPTY occurs fairly often with short data
sequences (e.g. write 1 byte), in those cases circbuf is usually empty
so no action on TXEMPTY would have been needed anyway. On the other
hand, longer data sequences make the race much more unlikely as UART
takes longer to consume the TX FIFO. Therefore it is rare for this race
to cause visible issues in general.
Fix the race by clearing the TXEMPTY bit in ISR *before* filling the
FIFO.
The TXEMPTY bit in ISR will only get asserted at the exact moment the
TX FIFO *becomes* empty, so clearing the bit before filling FIFO does
not cause an extra immediate assertion even if the FIFO is initially
empty.
This is hard to reproduce directly on a normal system, but inserting
e.g. udelay(200) after cdns_uart_handle_tx(port), setting 4000000 baud,
and then running "dd if=/dev/zero bs=128 of=/dev/ttyPS0 count=50"
reliably reproduces the issue on my ZynqMP test system unless this fix
is applied.
Fixes: 85baf542d5 ("tty: xuartps: support 64 byte FIFO size")
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Link: https://lore.kernel.org/r/20211026102741.2910441-1-anssi.hannula@bitwise.fi
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d02b006b29de14968ba4afa998bede0d55469e29 upstream.
This reverts commit 32262e2e429cdb31f9e957e997d53458762931b7.
The commit in question claims to determine the inverse of
serial8250_get_divisor() but failed to notice that some drivers override
the default implementation using a get_divisor() callback.
This means that the computed line-speed values can be completely wrong
and results in regular TCSETS requests failing (the incorrect values
would also be passed to any overridden set_divisor() callback).
Similarly, it also failed to honour the old (deprecated) ASYNC_SPD_FLAGS
and would break applications relying on those when re-encoding the
actual line speed.
There are also at least two quirks, UART_BUG_QUOT and an OMAP1510
workaround, which were happily ignored and that are now broken.
Finally, even if the offending commit were to be implemented correctly,
this is a new feature and not something which should be backported to
stable.
Cc: Pali Rohár <pali@kernel.org>
Fixes: 32262e2e429c ("serial: 8250: Fix reporting real baudrate value in c_ospeed field")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211007133146.28949-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 32262e2e429cdb31f9e957e997d53458762931b7 upstream.
In most cases it is not possible to set exact baudrate value to hardware.
So fix reporting real baudrate value which was set to hardware via c_ospeed
termios field. It can be retrieved by ioctl(TCGETS2) from userspace.
Real baudrate value is calculated from chosen hardware divisor and base
clock. It is implemented in a new function serial8250_compute_baud_rate()
which is inverse of serial8250_get_divisor() function.
With this change is fixed also UART timeout value (it is updated via
uart_update_timeout() function), which is calculated from the now fixed
baudrate value too.
Cc: stable@vger.kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20210927093704.19768-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
