CONFIG_EXT_SERIAL_IRQ_LEVEL is not available for thedefaultarchitecture x86.
Result is shown for architecture mn10300
default or selected kernelversion does not have config value CONFIG_EXT_SERIAL_IRQ_LEVEL.
Result is shown for kernelversion 6.7-rc3
External serial port interrupt priority
configname: CONFIG_EXT_SERIAL_IRQ_LEVEL
Linux Kernel Configuration
└─>Panasonic MN10300 system setup
└─>Interrupt request priority options
└─>External serial port interrupt priority