7545 Commits

Author SHA1 Message Date
Valentin Caron
2a3bcfe037 serial: stm32: fix flow control transfer in DMA mode
If flow control is enabled, framework will call stop_tx to
pause transfer and then call start_tx to resume transfer.

Clear USART_CR3_DMAT bit in stop_tx ops to pause DMA transfer.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220104182445.4195-4-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06 15:58:46 +01:00
Valentin Caron
9a135f16d2 serial: stm32: rework TX DMA state condition
TX DMA state condition is handled by tx_dma_busy boolean.
This boolean is set when dma descriptor is requested and reset when dma
channel is stopped (dma_terminate).

In stm32_usart_serial_remove(), stm32_usart_stop_tx() and
stm32_usart_transmit_chars_dma() fallback error case, DMA channel is
stopped but tx_dma_busy is not handled.

Rework the driver by using two new functions to solve this issue:
- stm32_usart_tx_dma_started return true if DMA TX have a descriptor.
- stm32_usart_tx_dma_enabled return true if DMAT bit is set.

stm32_usart_tx_dma_started uses tx_dma_busy flag to prevent dual DMA
transaction at the same time. This flag is set when a DMA transaction
begins and is unset when dmaengine_terminate_async function is called.
A new DMA transaction cannot be created if this flag is set.

Create a new function "stm32_usart_tx_dma_terminate" to be sure the flag
is unset after each call of dmaengine_terminate_async.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220104182445.4195-3-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06 15:58:46 +01:00
Valentin Caron
56a23f9319 serial: stm32: move tx dma terminate DMA to shutdown
Terminate DMA transaction and clear CR3_DMAT when shutdown is requested,
instead of when remove is requested. If DMA transfer is not stopped in
shutdown ops, driver will fail to start a new DMA transfer after next
startup ops.

Fixes: 3489187204eb ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220104182445.4195-2-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06 15:58:44 +01:00
Lukas Wunner
49a80424e3 serial: pl011: Drop redundant DTR/RTS preservation on close/open
Commit d8d8ffa47783 ("amba-pl011: do not disable RTS during shutdown")
amended the PL011 serial driver to leave DTR/RTS polarity untouched on
tty close.  That change made sense.

But the commit also added code to save DTR/RTS state to an internal
variable on tty close and restore it on tty open.  That part of the
commit makes less sense:  The driver has no ->pm() callback, so the uart
remains powered after tty close and automatically preserves register
state, including DTR/RTS.

Saving and restoring registers isn't the job of the ->startup() and
->shutdown() callbacks anyway.  Rather, it should happen in ->pm().

Additionally, after pl011_startup() restores the state, the serial core
overrides it in uart_port_dtr_rts() if a baud rate has been set:

tty_port_open()
  uart_port_activate()
    uart_startup()
      uart_port_startup()
        pl011_startup()       # restores DTR/RTS from uap->old_cr
  tty_port_block_til_ready()
    tty_port_raise_dtr_rts    # if (C_BAUD(tty))
      uart_dtr_rts()
        uart_port_dtr_rts()   # raises DTR/RTS

The serial core also overrides DTR/RTS on tty close in uart_shutdown()
if C_HUPCL(tty) is set.  So a user-defined DTR/RTS polarity won't
survive a close/open cycle anyway, unless the user has set the baud rate
to zero and disabled hupcl on the tty.

Bottom line is, the code to save and restore DTR/RTS has no effect.
Remove it.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/e22089ab49e6e78822c50c8c4db46bf3ee885623.1641129328.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06 15:56:52 +01:00
Lukas Wunner
e368cc656f serial: pl011: Drop CR register reset on set_termios
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>
2022-01-06 15:56:21 +01:00
Lukas Wunner
08a0c6dff9 serial: pl010: Drop CR register reset on set_termios
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>
2022-01-06 15:56:17 +01:00
Alyssa Ross
556172fabd serial: liteuart: fix MODULE_ALIAS
modprobe can't handle spaces in aliases.

Fixes: 1da81e5562fa ("drivers/tty/serial: add LiteUART driver")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Link: https://lore.kernel.org/r/20220104131030.1674733-1-hi@alyssa.is
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06 15:54:54 +01:00
Lad Prabhakar
0e479b460e serial: 8250_bcm7271: Fix return error code in case of dma_alloc_coherent() failure
In case of dma_alloc_coherent() failure return -ENOMEM instead of
returning -EINVAL.

Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220105180704.8989-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-06 15:53:49 +01:00
Greg Kroah-Hartman
99a507a8ea Revert "serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2"
This reverts commit d8e9a406a931f687945703a4bac45042eb81ce92.

It needs some future changes as pointed out by Johan and is not ready to
be merged just yet.

Reported-by: Johan Hovold <johan@kernel.org>
Cc: Magnus Damm <damm+renesas@opensource.se>
Link: https://lore.kernel.org/r/Yc7oZ/1tu95Z4wPS@hovoldconsulting.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-31 13:42:30 +01:00
Hans de Goede
0890186a96 serdev: Do not instantiate serdevs on boards with known bogus DSDT entries
x86 ACPI devices which ship with only Android as their factory image use
older kernels which do not yet support ACPI serdev enumeration, as such
the serdev information in their ACPI tables is not reliable.

For example on the Asus ME176C tablet the serdev describing the Bluetooth
HCI points to the serdev_controller connected to the GPS and the other way
around.

Use the new acpi_quirk_skip_serdev_enumeration() helper to identify
known boards with this issue and then either abort adding the serdev
controller (creating a tty cdev instead) or only create the controller
leaving the instantation of the serdev itself up to platform code.

In the case where only the serdev controller is created the necessary
serdevs will instead be instantiated by the
drivers/platform/x86/x86-android-tablets.c kernel module.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-30 19:01:42 +01:00
Lad Prabhakar
5acb78dc72 tty: goldfish: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224153753.22210-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:50:05 +01:00
Magnus Damm
d8e9a406a9 serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2
Allow serdev device drivers get notified by hardware errors such as BREAK,
FRAME, PARITY and OVERRUN.

With this patch, in the event of an error detected in the UART device driver
the serdev_device_driver will get the newly introduced ->error() callback
invoked if serdev_device_set_error_mask() has previously been used to enable
the type of error. The errors are taken straight from the TTY layer and fed
into the serdev_device_driver after filtering out only enabled errors.

Without this patch the hardware errors never reach the serdev_device_driver.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Link: https://lore.kernel.org/r/163931528842.27756.3665040315954968747.sendpatchset@octo
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:29:56 +01:00
Yu Tu
ad234e2bac tty: serial: meson: Drop the legacy compatible strings and clock code
All mainline .dts files have been using the stable UART since Linux
4.16. Drop the legacy compatible strings and related clock code.

Signed-off-by: Yu Tu <yu.tu@amlogic.com>
Link: https://lore.kernel.org/r/20211230102110.3861-2-yu.tu@amlogic.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:28:23 +01:00
Lad Prabhakar
e3b27e2f56 serial: pmac_zilog: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-11-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:49 +01:00
Lad Prabhakar
fc67c91329 serial: bcm63xx: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-10-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:49 +01:00
Lad Prabhakar
1129a63e3a serial: ar933x: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-9-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:49 +01:00
Lad Prabhakar
f63f1ddb5c serial: vt8500: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-8-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:49 +01:00
Lad Prabhakar
60302276ca serial: altera_jtaguart: Use platform_get_irq_optional() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-7-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:49 +01:00
Lad Prabhakar
6050efac12 serial: pxa: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-6-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:49 +01:00
Lad Prabhakar
5b68061983 serial: meson: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-5-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:48 +01:00
Lad Prabhakar
c195438f1e serial: 8250_bcm7271: Propagate error codes from brcmuart_probe()
In case of failures brcmuart_probe() always returned -ENODEV, this
isn't correct for example platform_get_irq_byname() may return
-EPROBE_DEFER to handle such cases propagate error codes in
brcmuart_probe() in case of failures.

Fixes: 41a469482de25 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-4-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:48 +01:00
Lad Prabhakar
56c8b1c10e serial: 8250_bcm7271: Use platform_get_irq() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:48 +01:00
Lad Prabhakar
257538544d serial: altera: Use platform_get_irq_optional() to get the interrupt
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-2-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:26:48 +01:00
Muhammad Usama Anjum
cb559bb974 serial: lantiq: store and compare return status correctly
platform_get_irq() returns signed status. It should be stored and
compared as signed value before storing to unsigned variable. Implicit
conversion from signed to unsigned and then comparison with less than
zero is wrong as unsigned value can never be less than zero.

Fixes: f087f01ca2c5 ("serial: lantiq: Use platform_get_irq() to get the interrupt")
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/YcIf7+oSWWn34ND6@debian-BULLSEYE-live-builder-AMD64
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:23:46 +01:00
Lukas Wunner
b4a29b9480 serial: 8250: Move Alpha-specific quirk out of the core
struct uart_8250_port contains mcr_mask and mcr_force members whose
sole purpose is to work around an Alpha-specific quirk.  This code
doesn't belong in the core where it is executed by everyone else,
so move it to a proper ->set_mctrl callback which is used on the
affected Alpha machine only.

The quirk was introduced in January 1995:
https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/diff/drivers/char/serial.c?h=1.1.83

The members in struct uart_8250_port were added in 2002:
https://git.kernel.org/history/history/c/4524aad27854

The quirk applies to non-PCI Alphas and arch/alpha/Kconfig specifies
"select FORCE_PCI if !ALPHA_JENSEN".  So apparently the only affected
machine is the EISA-based Jensen that Linus was working on back then:
https://lore.kernel.org/all/CAHk-=wj1JWZ3sCrGz16nxEj7=0O+srMg6Ah3iPTDXSPKEws_SA@mail.gmail.com/

Up until now the quirk is not applied unless CONFIG_PCI is disabled.
If users forget to do that or run a generic Alpha kernel, the serial
ports aren't usable on Jensen.  Avoid by confining the quirk to
CONFIG_ALPHA_JENSEN instead of !CONFIG_PCI.  On generic Alpha kernels,
auto-detect at runtime whether the quirk needs to be applied.

Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Ulrich Teichert <krypton@ulrich-teichert.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/b83d069cb516549b8a5420e097bb6bdd806f36fc.1640695609.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:23:44 +01:00
Lukas Wunner
d3b3404df3 serial: Fix incorrect rs485 polarity on uart open
Commit a6845e1e1b78 ("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: a6845e1e1b78 ("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>
2021-12-30 13:21:02 +01:00
Wander Lairson Costa
5021d709b3 tty: serial: Use fifo in 8250 console driver
Note: I am using a small test app + driver located at [0] for the
problem description. serco is a driver whose write function dispatches
to the serial controller. sertest is a user-mode app that writes n bytes
to the serial console using the serco driver.

While investigating a bug in the RHEL kernel, I noticed that the serial
console throughput is way below the configured speed of 115200 bps in
a HP Proliant DL380 Gen9. I was expecting something above 10KB/s, but
I got 2.5KB/s.

$ time ./sertest -n 2500 /tmp/serco

real    0m0.997s
user    0m0.000s
sys     0m0.997s

With the help of the function tracer, I then noticed the serial
controller was taking around 410us seconds to dispatch one single byte:

$ trace-cmd record -p function_graph -g serial8250_console_write \
   ./sertest -n 1 /tmp/serco

$ trace-cmd report

            |  serial8250_console_write() {
 0.384 us   |    _raw_spin_lock_irqsave();
 1.836 us   |    io_serial_in();
 1.667 us   |    io_serial_out();
            |    uart_console_write() {
            |      serial8250_console_putchar() {
            |        wait_for_xmitr() {
 1.870 us   |          io_serial_in();
 2.238 us   |        }
 1.737 us   |        io_serial_out();
 4.318 us   |      }
 4.675 us   |    }
            |    wait_for_xmitr() {
 1.635 us   |      io_serial_in();
            |      __const_udelay() {
 1.125 us   |        delay_tsc();
 1.429 us   |      }
...
...
...
 1.683 us   |      io_serial_in();
            |      __const_udelay() {
 1.248 us   |        delay_tsc();
 1.486 us   |      }
 1.671 us   |      io_serial_in();
 411.342 us |    }

In another machine, I measured a throughput of 11.5KB/s, with the serial
controller taking between 80-90us to send each byte. That matches the
expected throughput for a configuration of 115200 bps.

This patch changes the serial8250_console_write to use the 16550 fifo
if available. In my benchmarks I got around 25% improvement in the slow
machine, and no performance penalty in the fast machine.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Link: https://lore.kernel.org/r/20211222112831.1968392-2-wander@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-30 13:19:49 +01:00
lianzhi chang
fb09d0ac07 tty: Fix the keyboard led light display problem
Use the "ctrl+alt+Fn" key combination to switch the system from tty to
desktop or switch the system from desktop to tty. After the switch is
completed, it is found that the state of the keyboard lock is
inconsistent with the state of the keyboard Led light.The reasons are
as follows:

* The desktop environment (Xorg and other services) is bound to a tty
  (assuming it is tty1), and the kb->kbdmode attribute value of tty1
  will be set to VC_OFF. According to the current code logic, in the
  desktop environment, the values of ledstate and kb->ledflagstate
  of tty1 will not be modified anymore, so they are always 0.

* When switching between each tty, the final value of ledstate set by
  the previous tty is compared with the kb->ledflagstate value of the
  current tty to determine whether to set the state of the keyboard
  light. The process of switching between desktop and tty is also the
  process of switching between tty1 and other ttys. There are two
  situations:

  - (1) In the desktop environment, tty1 will not set the ledstate,
  which will cause when switching from the desktop to other ttys,
  if the desktop lights up the keyboard's led, after the switch is
  completed, the keyboard's led light will always be on;

  - (2) When switching from another tty to the desktop, this
  mechanism will trigger tty1 to set the led state. If other tty
  lights up the led of the keyboard before switching to the desktop,
  the led will be forcibly turned off. This situation should
  be avoided.

* The current patch is to solve these problems: When VT is switched,
  the keyboard led needs to be set once.Ensure that after the
  switch is completed, the state of the keyboard LED is consistent
  with the state of the keyboard lock.

Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: lianzhi chang <changlianzhi@uniontech.com>
Link: https://lore.kernel.org/r/20211215125125.10554-1-changlianzhi@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-21 09:19:14 +01:00
Andy Shevchenko
d6d9d17aba tty: tty_io: Switch to vmalloc() fallback in case of TTY_NO_WRITE_SPLIT
When TTY_NO_WRITE_SPLIT is set and 64 KiB chunks are used, allow
vmalloc() fallback. Supply __GFP_RETRY_MAYFAIL to make kmalloc()
preferable over vmalloc() since we may want a better performance.

Note, both current users copy data to another buffer anyway, so
the type of our allocation doesn't affect their expectations.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211220133250.3070-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-21 09:18:44 +01:00
Xiang wangx
e822b4973f tty/ldsem: Fix syntax errors in comments
Delete the redundant word 'are'.

Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20211208142036.7956-1-wangxiang@cdjrlc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-21 09:15:49 +01:00
Magnus Damm
712fe4c849 serial: sh-sci: Remove BREAK/FRAME/PARITY/OVERRUN printouts
Update the SCIF serial driver to remove printouts for break, frame, parity
and overrun errors. This reduces the amount of console printouts generated
by the defconfig kernel on R-Car Gen3 for certain use cases. To retrieve
more information about such errors the user may inspect counters. Also these
errors are fed into the TTY layer for further application specific handling.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Link: https://lore.kernel.org/r/163884254093.18109.2982470198301927679.sendpatchset@octo
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:55:56 +01:00
Andy Shevchenko
46dacba8fe serial: 8250_pericom: Use serial_dl_write() instead of open coded
It's better to stick with standard API to write and read DL value
when the hardware is compatible with it. In case any quirks are
needed it may be easily added in one place rather than modifying
code here and there.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211122133512.8947-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:55:22 +01:00
Jay Dolan
b4ccaf5aa2 serial: 8250_pericom: Re-enable higher baud rates
Add UPF_MAGIC_MULTIPLIER to the port flags since there is now
range checking in serial8250_get_baud_rate() in 8250_port.c.

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/20211122133512.8947-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:55:22 +01:00
Andy Shevchenko
fcfd3c09f4 serial: 8250_pci: Split out Pericom driver
Pericom along with Acces I/O support consumes a lot of LOCs in 8250_pci.c.
For the sake of easier maintenance, split it to a separate driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211122133512.8947-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:55:22 +01:00
Sam Protsenko
8cf8d3c4a6 tty: serial: samsung: Fix console registration from module
On modern Exynos SoCs (like Exynos850) the UART can be implemented as a
part of USI IP-core. In such case, USI driver is used to initialize USI
registers, and it also calls of_platform_populate() to instantiate all
sub-nodes (e.g. serial node) of USI node. When serial driver is
built-in, but USI driver is a module, and CONFIG_SERIAL_SAMSUNG_CONSOLE
is enabled, next call chain will happen when loading USI module from
user space:

    usi_init
      v
    usi_probe
      v
    of_platform_populate
      v
    s3c24xx_serial_probe
      v
    uart_add_one_port
      v
    uart_configure_port
      v
    register_console
      v
    try_enable_new_console
      v
    s3c24xx_serial_console_setup

But because the serial driver is built-in, and
s3c24xx_serial_console_setup() is marked with __init keyword, that
symbol will discarded and long gone by that time already, causing failed
paging request.

That happens during the next config combination:

    EXYNOS_USI=m
    SERIAL_SAMSUNG=y
    SERIAL_SAMSUNG_CONSOLE=y

That config should be completely possible, so rather than limiting
SERIAL_SAMSUNG choice to "m" only when USI=m, remove __init keyword for
all affected functions.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211204195757.8600-6-semen.protsenko@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:54:37 +01:00
Sam Protsenko
0882b473b0 tty: serial: samsung: Enable console as module
Enable serial driver to be built as a module. To do so, init the console
support on driver/module load instead of using console_initcall().

Inspired by commit 87a0b9f98ac5 ("tty: serial: meson: enable console as
module").

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211204195757.8600-5-semen.protsenko@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:54:10 +01:00
Sam Protsenko
59f37b7370 tty: serial: samsung: Remove USI initialization
USI control is now extracted to the dedicated USI driver. Remove USI
related code from serial driver to avoid conflicts and code duplication.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211204195757.8600-4-semen.protsenko@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 16:53:44 +01:00
Linus Torvalds
59b3f94488 Merge branch 'xsa' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Merge xen fixes from Juergen Gross:
 "Fixes for two issues related to Xen and malicious guests:

   - Guest can force the netback driver to hog large amounts of memory

   - Denial of Service in other guests due to event storms"

* 'xsa' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/netback: don't queue unlimited number of packages
  xen/netback: fix rx queue stall detection
  xen/console: harden hvc_xen against event channel storms
  xen/netfront: harden netfront against event channel storms
  xen/blkfront: harden blkfront against event channel storms
2021-12-20 07:42:21 -08:00
Greg Kroah-Hartman
35eaa42c4a Linux 5.16-rc6
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Merge 5.16-rc6 into tty-next

We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20 10:00:30 +01:00
Colin Ian King
4b95391c8e serial: 8250_pci: remove redundant assignment to tmp after the mask operation
The variable tmp is being masked with a bitmask and the value is being
written to port base + 0x3c.  However, the masked value is being written
back to tmp and tmp is never used after this. The assignmentment is
redundant, replace the &= operator with just &.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewesd-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211205232822.110099-1-colin.i.king@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 18:01:39 +01:00
Jesse Taube
443df57b31 tty: serial: fsl_lpuart: Add i.MXRT1050 support
Add support for i.MXRT1050's uart.

Cc: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
Link: https://lore.kernel.org/r/20211215220538.4180616-8-Mr.Bossman075@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 18:00:21 +01:00
Rob Herring
5bb221b0ad serial: atmel: Use platform_get_irq() to get the interrupt
Accessing platform device resources directly has long been deprecated for
DT as IRQ resources may not be available at device creation time. Drivers
continuing to use static IRQ resources is blocking removing the static setup
from the DT core code.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211215224832.1985402-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 17:57:37 +01:00
Geert Uytterhoeven
8a1dcae95c serial: sh-sci: Use devm_clk_get_optional()
The sh-sci driver supports up to four input clocks, of which only the
first one is mandatory.

Replace devm_clk_get() and custom error checking by
devm_clk_get_optional(), to simplify the code and to catch all real
errors.

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/bce27288cb570952dd96b441e1af8768ad8b4870.1639663832.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 17:57:15 +01:00
Geert Uytterhoeven
0d1bc829a7 serial: sh-sci: Use dev_err_probe()
Use the dev_err_probe() helper to streamline error handling.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/5c4dd8df1f8d0d14786f26ee80b77f3eb8e06cd5.1639663832.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 17:57:15 +01:00
Geert Uytterhoeven
09c7bda4dd serial: sh-sci: Drop support for "sci_ick" clock
Since commit 1b463bd51042927e ("ARM: dts: r8a7794: Rename the serial
port clock to fck") in v4.6, all upstream DTS files call the SCIF
functional clock "fck".

Hence the time is ripe to drop backward-compatibility with old DTBs that
use the old "sci_ick" name.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/b4103e44d6ac46b6c1c264e2aeac80b39941fe74.1639663832.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 17:57:15 +01:00
Rob Herring
f087f01ca2 serial: lantiq: Use platform_get_irq() to get the interrupt
Use the preferred platform_get_irq() call to retrieve the interrupts. These
have the advantage of working with deferred probe and gets us one step
closer to removing of_irq_to_resource_table().

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211215224800.1984391-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 17:56:34 +01:00
Yoshihiro Shimoda
26baf4b66c tty: serial: sh-sci: Add support for R-Car Gen4
Add serial support for R-Car Gen4 SoC.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20211209070817.1223888-3-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 17:56:03 +01:00
Arnd Bergmann
03de6b2738 dmaengine: qcom-adm: stop abusing slave_id config
The slave_id was previously used to pick one DMA slave instead of another,
but this is now done through the DMA descriptors in device tree.

For the qcom_adm driver, the configuration is documented in the DT
binding to contain a tuple of device identifier and a "crci" field,
but the implementation ends up using only a single cell for identifying
the slave, with the crci getting passed in nonstandard properties of
the device, and passed through the dma driver using the old slave_id
field. Part of the problem apparently is that the nand driver ends up
using only a single DMA request ID, but requires distinct values for
"crci" depending on the type of transfer.

Change both the dmaengine driver and the two slave drivers to allow
the documented binding to work in addition to the ad-hoc passing
of crci values. In order to no longer abuse the slave_id field, pass
the data using the "peripheral_config" mechanism instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211122222203.4103644-9-arnd@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-12-17 11:23:56 +05:30
Emil Renner Berthing
b0ad20a3b6 serial: 8250_dw: Add StarFive JH7100 quirk
On the StarFive JH7100 RISC-V SoC the UART core clocks can't be set to
exactly 16 * 115200Hz and many other common bitrates. Trying this will
only result in a higher input clock, but low enough that the UART's
internal divisor can't come close enough to the baud rate target.
So rather than try to set the input clock it's better to skip the
clk_set_rate call and rely solely on the UART's internal divisor.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
2021-12-16 17:24:23 +01:00
Juergen Gross
fe415186b4 xen/console: harden hvc_xen against event channel storms
The Xen console driver is still vulnerable for an attack via excessive
number of events sent by the backend. Fix that by using a lateeoi event
channel.

For the normal domU initial console this requires the introduction of
bind_evtchn_to_irq_lateeoi() as there is no xenbus device available
at the time the event channel is bound to the irq.

As the decision whether an interrupt was spurious or not requires to
test for bytes having been read from the backend, move sending the
event into the if statement, as sending an event without having found
any bytes to be read is making no sense at all.

This is part of XSA-391

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V2:
- slightly adapt spurious irq detection (Jan Beulich)
V3:
- fix spurious irq detection (Jan Beulich)
2021-12-16 08:24:08 +01:00