The issue is depicted as title.
The following is the sequence of register setting to reproduce it.
#Enable enhanced function and Auto RTS/CTS
set 0x3 0xbf
set 0x2 0xd0
#Exit enhanced regist, Set 8N1
set 0x3 0x3
#Set 115200 8N1
set 0x3 0x83
set 0x0 0x8
set 0x1 0x0
set 0x7 0x0
set 0x3 0x03
#Enable INT pin, RTS/DTR
set 0x4 0x0b
#Init FIFO
set 0x4 0x4b
#Set TCR 32/96
set 0x6 0x4c
#Set TLR 96/0
set 0x7 0xc0
set 0x4 0x0b
set 0x2 0x06
set 0x2 0x01
#Deassert RTS from opposite serial port
#Send some data to THR
set 0x00 0x33
set 0x00 0x34
set 0x00 0x35
#Read LSR and confirm the TX is no empty
read 0x05 = 0x00
#Enable the THR interrupt in IER, I expect the interrupt should not be triggered.
set 0x01 0x02
#Interrupt service routine is served here.
