CONFIG_ETRAX_SERIAL_PORT1_DMA5_IN is not available for thedefaultarchitecture x86.
Result is shown for architecture cris
default or selected kernelversion does not have config value CONFIG_ETRAX_SERIAL_PORT1_DMA5_IN.
Result is shown for kernelversion 6.7-rc3

Ser1 uses DMA5 for input


Ser1 DMA in channel
└─>Ser1 uses DMA5 for input
In linux kernel since version 2.6.13 (release Date: 2005-08-28)  
Enables the DMA5 input channel for ser1 (ttyS1).
If you do not enable DMA, an interrupt for each character will be
used when receiving data.
Normally you want this on, unless you use the DMA channel for
something else.