LibreELEC v8.90.004 : no UI

    Hello,

    I recently bought an AREZ Radeon RX550 to test 4K and HDR2SDR, but kodi never lauched. With only fresh installs :

    • LibreELEC 8.2.5 : error message about Flexbox
    • LibreELEC 8.90.004 : LibreELEC splash screen displayed, system booted (see DLNA) but Kodi not launched
    • LibreELEC build #0912 : same as above

    About my hardware :

    • MB : ASRock FM2A88M Extreme4+
    • CPU : AMD A6-6400K (3.9 GHz) Black Edition
    • GPU : AREZ Radeon RX550 (2GB)
    • TV : TV Panasonic TX-55CX700E UHD
    • HDMI : KabelDirekt HDMI 4K (2.0)

    Maybe the system is confuse by having both the RX 550 and the Radeon HD 8470D of the A6-6400K CPU.

    To get more information you can remove the RX 550 card. Configure network and sshd in the recent Milhouse build and test the ssh access over network.

    Insert the RX 550 again. After boot network access should be still possible. Please post the results of:

    Code
    dmesg|paste
journalctl|paste
paste /var/log/Xorg.0.log

    Sorry for my late answer and thank you for yours.

    My BIOS is configured to boot on PCI graphic card : 1537087792.jpg

    I did some tests on Debian and Ubuntu with XFCE:

    • Debian buster: need firmware-amd-graphics
    • Ubuntu 18.04.1: works at boot

    On Ubuntu I tried with the drivers from the AMD website, but impossible to change resolution to UHD (black screen). Still on Ubuntu, with Kodi 18, I had the hardware decoding of the HEVC but no audio passthrough.

    Edited 5 times, last by sk4hrr: Sorry about my approximate English. (September 16, 2018 at 6:04 PM).

    The kernel of 8.2.5 is to old for RX550 support.

    On 8.90.004 the kernel activates the radeon driver for HD 8470D and the amdgpu driver for the RX550. The system detects the radeon driver first and configures xorg for it.

    Try:

    Bash
    sed '/DRIVER=="radeon"/d' </lib/udev/rules.d/97-xorg.rules >~/.config/udev.rules.d/97-xorg.rules

    to remove radeon detection and reboot.

    Now amdgpu driver is loaded and your monitor is detected. But the radeon driver is loaded too and xorg does crash.

    Two Ideas:

    - Disable the onboard graphics of the A6-6400K in BIOS configuration if possible.

    - Disable the radeon kernel driver:

    Code
    mount -o remount,rw /flash
nano /flash/syslinux.cfg

    Add initcall_blacklist=radeon_init to the APPEND line, save and reboot.

    Edited once, last by mglae: mount command fixed (September 17, 2018 at 10:25 PM).

    Quote from sk4hrr

    Disabling the A6 GPU does not change anything: 1537209101.jpg

    But, your tips works, but with this command:

    Code
    mount -t vfat -o rw,remount /dev/sda1 /flash

    Thanks, fixed my post.

    Quote

    Should I do that every time I update?

    No, an update does not change syslinux.cfg.

    Without kernel radeon driver ~/.config/udev.rules.d/97-xorg.rules is not needed any more, delete it.

    Quote from mglae

    Without kernel radeon driver ~/.config/udev.rules.d/97-xorg.rules is not needed any more, delete it.

    After I test on the latest nightly build (#0916), I did a test on fresh install of 8.90.005 release. So, it's already deleted, thanks.

    Start-up problem solved, but conversion from HDR to SDR not. Too bad. Thank you for your help!