:orphan:

.. title:: CONFIG_UART_NS16550_WA_ISR_REENABLE_INTERRUPT

.. kconfig:: CONFIG_UART_NS16550_WA_ISR_REENABLE_INTERRUPT

CONFIG_UART_NS16550_WA_ISR_REENABLE_INTERRUPT
#############################################

*Re-enable interrupts by toggling IER at end of ISR*

Type: ``bool``

Help
====

.. code-block:: none

    In some configurations (e.g. edge interrupt triggers),
    an interruptible event occurs during ISR and the host interrupt
    controller does not see the new event due to IIR is constantly
    asserting interrupts. For example, the callback handles RX and
    then TX. If another character comes in before end of TX processing
    (TX interrupt still asserts while raising RX interrupt), the host
    interrupt controller may not see this new event. So if needed,
    the IER is being toggled to re-assert interrupts at the end of ISR
    to nudge the host interrupt controller to fire the ISR again.

Direct dependencies
===================

(\ :kconfig:`UART_NS16550 <CONFIG_UART_NS16550>` && \ :kconfig:`SOC_SERIES_RISCV32_IT8XXX2 <CONFIG_SOC_SERIES_RISCV32_IT8XXX2>`) || (\ :kconfig:`UART_INTERRUPT_DRIVEN <CONFIG_UART_INTERRUPT_DRIVEN>` && \ :kconfig:`UART_NS16550 <CONFIG_UART_NS16550>` && \ :kconfig:`SERIAL <CONFIG_SERIAL>`)

*(Includes any dependencies from ifs and menus.)*

Default
=======

- y

Kconfig definitions
===================



At ``<SoC>/riscv/riscv-ite/it8xxx2/Kconfig.defconfig.series:32``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:27`` → ``<SoC>/riscv/riscv-ite/Kconfig.defconfig:4``

Menu path: (Top)

.. code-block:: kconfig

    config UART_NS16550_WA_ISR_REENABLE_INTERRUPT
    	bool
    	default y
    	depends on UART_NS16550 && SOC_SERIES_RISCV32_IT8XXX2

----

At ``<Driver>/serial/Kconfig.ns16550:46``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:42`` → ``<Driver>/Kconfig:26`` → ``<Driver>/serial/Kconfig:104``

Menu path: (Top) → Device Drivers → Serial Drivers → NS16550 serial driver → NS16550 Workarounds

.. code-block:: kconfig

    config UART_NS16550_WA_ISR_REENABLE_INTERRUPT
    	bool "Re-enable interrupts by toggling IER at end of ISR"
    	depends on UART_INTERRUPT_DRIVEN && UART_NS16550 && SERIAL
    	help
    	  In some configurations (e.g. edge interrupt triggers),
    	  an interruptible event occurs during ISR and the host interrupt
    	  controller does not see the new event due to IIR is constantly
    	  asserting interrupts. For example, the callback handles RX and
    	  then TX. If another character comes in before end of TX processing
    	  (TX interrupt still asserts while raising RX interrupt), the host
    	  interrupt controller may not see this new event. So if needed,
    	  the IER is being toggled to re-assert interrupts at the end of ISR
    	  to nudge the host interrupt controller to fire the ISR again.

*(The 'depends on' condition includes propagated dependencies from ifs and menus.)*