The JH7110 uses a DesignWare UART component which has some "interesting" extra features. The spurious interrupts are probably caused by a busy interrupt generated by the UART (which is caused by writing the LCR when the chip is busy). If this interrupt is not cleared, you'll end up in an interrupt storm.
The JH7110 uses a DesignWare UART component which has some "interesting" extra features. The spurious interrupts are probably caused by a busy interrupt generated by the UART (which is caused by writing the LCR when the chip is busy). If this interrupt is not cleared, you'll end up in an interrupt storm.
See e.g. the [Linux DesignWare UART driver] for a workaround (https://elixir.bootlin.com/linux/latest/source/drivers/tty/serial/8250/8250_dw.c).