RK3399 HDMI audio quality

  • hi mo123,

    i have now integrated the Rockchip change for the Rockpi4 device tree.

    But do not know exactly whether the problem could be.

    Here is the dtb file.


    I also saw if I use an old u-boot package >5 months ago then LE also boots correctly again on every device.

    You don't perhaps know how fans work on RK3399?

    The Khadas Edge also has a fan like the nanopi4(rk3399-nanopi4-common.dtsi) but I can't seem to get it turning on automatically on LE with the 4.4 kernel. With mainline LE, the fan is working.

    If I use the NanoPi4 dts file, the fan starts spinning on the Edge but obviously doesn't boot because it's the incorrect dts/dtb used.

    Here is a kernel fan patch but I think it's for Android and not Linux(LE) - FAN: enable PWM FAN, add auto mode and factory test support · khadas/[email protected] · GitHub. The fan has 0 1 2 3 speeds, if it can automatically use speed 1, low speed, it would be great.

    The device runs quite hot if software decoding 1080p so having the fan work would be helpful with the older 4.4 kernel.

  • Hi

    Do you know how to add the 'add 'uboot-set' in io-domain node' for Edge RK3399?

    The same patch of nanopi added to rk3399-khadas-edge.dtsi doesn't seem to boot, only if I use an older u-boot.

    Here are all the specific Edge Linux 4.4 kernel changes

    Commits · khadas/linux · GitHub

    I'll try to add and check what is different compared to your kernel to make the device more compatible.

    RockPi 4 with a heatsink works great so far and stays cool.

    Not sure why Khadas decided to use a noisy fan.

    The fan is working with LibreELEC with mainline kernel.

    I still couldn't get the fan working with the 4.4 kernel even with 8018716dd73adc85c8f5175290066bf6d5b4e70a commit, but maybe it's because I tested with an old u-boot or more kernel changes are missing, not sure.


  • Hi m0123,

    For me it is not necessary.

    The system based on kernel 4.4 is stable for my needs.

    I will use LE 10 with the mainline kernel if the rk3399 support is stable.