ef0d955758
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. Signed-off-by: Daniel Leung <daniel.leung@intel.com>
63 lines
1.9 KiB
Plaintext
63 lines
1.9 KiB
Plaintext
# SPDX-License-Identifier: Apache-2.0
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menuconfig UART_NS16550
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bool "NS16550 serial driver"
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select SERIAL_HAS_DRIVER
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select SERIAL_SUPPORT_INTERRUPT
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help
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This option enables the NS16550 serial driver.
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This driver can be used for the serial hardware
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available on x86 boards.
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if UART_NS16550
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config UART_NS16550_LINE_CTRL
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bool "Enable Serial Line Control for Apps"
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depends on UART_LINE_CTRL
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help
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This enables the API for apps to control the serial line,
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such as CTS and RTS.
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Says n if not sure.
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config UART_NS16550_DRV_CMD
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bool "Enable Driver Commands"
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depends on UART_DRV_CMD
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help
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This enables the API for apps to send commands to driver.
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Says n if not sure.
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config UART_NS16750
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bool "Enable UART 16750 (64-bytes FIFO and auto flow control)"
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help
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This enables support for 64-bytes FIFO and automatic hardware
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flow control if UART controller is 16750.
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config UART_NS16550_ACCESS_WORD_ONLY
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bool "NS16550 only allows word access"
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help
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In some case, e.g. ARC HS Development kit, the peripheral space of ns
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16550 (DesignWare UART) only allows word access, byte access will raise
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exception.
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menu "NS16550 Workarounds"
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config UART_NS16550_WA_ISR_REENABLE_INTERRUPT
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bool "Re-enable interrupts by toggling IER at end of ISR"
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depends on UART_INTERRUPT_DRIVEN
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help
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In some configurations (e.g. edge interrupt triggers),
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an interruptible event occurs during ISR and the host interrupt
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controller does not see the new event due to IIR is constantly
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asserting interrupts. For example, the callback handles RX and
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then TX. If another character comes in before end of TX processing
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(TX interrupt still asserts while raising RX interrupt), the host
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interrupt controller may not see this new event. So if needed,
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the IER is being toggled to re-assert interrupts at the end of ISR
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to nudge the host interrupt controller to fire the ISR again.
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endmenu
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endif # UART_NS16550
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