• Bug#1106135: linux-image-6.12.29-loong64: display driver of loongson 7A

    From Jianfeng Liu@1:229/2 to All on Tue May 20 09:10:02 2025
    XPost: linux.debian.bugs.dist
    From: liujianfeng1994@gmail.com

    Package: src:linux
    Version: 6.12.29-1
    Severity: important
    Tags: patch

    Linux kernel has included the display controller driver of Loongson ls7a1000/ls7a2000 since v6.6.
    Now the kernel from debian doesn't enable it. When booting with monitor connected to the HDMI port
    on motherboard with 7A2000 north bridge chip, there is no drm support, gnome can only run with X11
    session. Output of ls -l /sys/class/drm/:
    total 0
    -r--r--r-- 1 root root 16384 May 20 14:47 version

    After enabling CONFIG_DRM_LOONGSON, I can run gnome wayland session.

    Here is the patch for debian:
    diff --git a/debian/config/loong64/config b/debian/config/loong64/config
    index 5dcde27..6c37250 100644
    --- a/debian/config/loong64/config
    +++ b/debian/config/loong64/config
    @@ -70,6 +70,11 @@ CONFIG_DRM=m
    ##
    CONFIG_DRM_AST=m

    +##
    +## file: drivers/gpu/drm/loongson/Kconfig
    +##
    +CONFIG_DRM_LOONGSON=m
    +
    ##
    ## file: drivers/gpu/drm/radeon/Kconfig
    ##


    -- Package-specific info:
    ** Version:
    Linux version 6.12.29-loong64 (debian-kernel@lists.debian.org) (loongarch64-linux-gnu-gcc-14 (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44) #1 SMP Debian 6.12.29-1 (2025-05-18)

    ** Command line:
    BOOT_IMAGE=/boot/vmlinuz-6.12.29-loong64 root=UUID=4008c546-bdbc-44ac-ab5f-1231de049a3c ro radeon.si_support=0 amdgpu.si_support=1 radeon.cik_support=0 amdgpu.cik_support=1 quiet

    ** Tainted: OE (12288)
    * externally-built ("out-of-tree") module was loaded
    * unsigned module was loaded

    ** Kernel log:
    [ 5.877079] systemd[1]: Mounted sys-fs-fuse-connections.mount - FUSE Control File System.
    [ 5.877228] systemd[1]: Mounted sys-kernel-config.mount - Kernel Configuration File System.