DisplayPort MST (Multi-Stream Transport) Support - 3-to-1 DP Hub Not Working

[acorns]

I’m trying to use a 3-to-1 DisplayPort hub but it’s not being detected. After troubleshooting, I believe Garuda’s kernel may not have MST support compiled in.

What I’ve searched/tried:

• Checked /sys/class/drm/card1-DP-2/ - no mst_mgr directory exists
• Loaded relevant modules: drm_display_helper and drm_kms_helper
• Searched kernel config for MST support: zcat /proc/config.gz | grep -i -E "(MST|DP_)" - no MST-related configs found
• Hub works fine on other systems with MST support

Current status:

• Hub is detected as connected on card1-DP-2
• xrandr only shows the main DP-2 output, not individual hub ports (DP-2-1, DP-2-2, DP-2-3)
• No MST manager interface available

Question: Does Garuda’s default kernel include CONFIG_DRM_DP_MST_TOPOLOGY support? If not, would switching to linux-zen provide MST support, or do I need to look at other solutions?

[Technetium]

Can you please provide garuda-inxi? The default kernel varies. Try Zen and Cachyos.
Also try

Monitor stays in sleep when daisy chained via DisplayPort

I don’t see a config option for MST: ITE IT6505 DisplayPort bridge - CONFIG_DRM_ITE_IT6505 - ite-it6505.ko - kernelconfig.iosupport for simple Embedded DisplayPort panels - CONFIG_DRM_PANEL_EDP - panel-edp.ko - kernelconfig.ioZynqMP DisplayPort Controller Driver - CONFIG_DRM_ZYNQMP_DPSUB - zynqmp-dpsub.ko - kernelconfig.ioBuild HDMI/DisplayPort HD-audio codec support - CONFIG_SND_HDA_CODEC_HDMI - snd-hda-codec-hdmi.ko - kernelconfig.ioDisplayPort Alternate Mode driver - CONFIG_TYPEC_DP_ALTMODE - typec_displayport.ko - kernelconfig.ioEnable DisplayPort CEC-Tunneling-over-AUX HDMI support - CONFIG_DRM_DISPLAY_DP_AUX_CEC - - kernelconfig.ioEnable DisplayPort CEC-Tunneling-over-AUX HDMI support - CONFIG_DRM_DP_CEC - - kernelconfig.ioEnable DisplayPort support in MSM DRM driver - CONFIG_DRM_MSM_DP - - kernelconfig.ioZynqMP DisplayPort Audio Support - CONFIG_DRM_ZYNQMP_DPSUB_AUDIO - - kernelconfig.io