ok... My box has a AV port , but no AV port audio output (I have test with a 3.5mm jack earphone, and use meson-gxl-s805x-p241.dts to boot)
Unfortunately , I didn't found any DAC chip on board. But only found a amplifier chip (TPF605) on board.
By the way , Box is mgv2000 , board id is gxlx_p261_1g, I'm use DTC convert dtb to dts.
So , I guess it need these driver , and maybe my guess is wrong . Could you give me some suggestion about how to make audio output work on AV port?