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No dual monitor MST video through USBC hub until suspend/resume

How to reproduce

Boot the computer, attach the USBC-Hub (which has 2 displays via HDMI + DP connected) and get no video.
Then on 6.11 it works to run systemctl suspend and then pushing the power button again to resume to get video on both monitors.
If only using the 1st HDMI port it always work without such a cycle, the other ports even alone also never work.
(On 6.12=drm-tip the suspend itself freezes)

Tested kernel versions (logs attached)

(arch) Linux version 6.11.7-arch1-1 (linux@archlinux) (gcc (GCC) 14.2.1 20240910, GNU ld (GNU Binutils) 2.43.0) #1 (moved) SMP PREEMPT_DYNAMIC Fri, 08 Nov 2024 17:57:56 +0000.
I've also confirmed using xe kernel driver instead makes no difference.

(drm-tip) Linux version 6.12.0-rc7-g52166ab72753 (steffen@steffen-zenbook) (gcc (GCC) 14.2.1 20240910, GNU ld (GNU Binutils) 2.43.0) #1 (moved) SMP PREEMPT_DYNAMIC Thu Nov 14 09:07:01 CET 2024

lspci

0000:00:02.0 VGA compatible controller [0300]: Intel Corporation Meteor Lake-P [Intel Arc Graphics] [8086:7d55] (rev 08) (prog-if 00 [VGA controller])
	DeviceName: VGA
	Subsystem: ASUSTeK Computer Inc. Device [1043:1a63]
	Flags: bus master, fast devsel, latency 0, IRQ 124, IOMMU group 0
	Memory at 5010000000 (64-bit, prefetchable) [size=16M]
	Memory at 4000000000 (64-bit, prefetchable) [size=256M]
	Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: i915
	Kernel modules: i915, xe

Used hardware

Asus Zenbook UX3405MA Anker 575 12 in 1 USBC Hub (not the docking station 13 in 1 variant!)

Attached logs

dmesg.txt 6.12 drmtip only initial boot cycle no video on external monitors.

dmesg611_suspend.txt 6.11 kernel which has hub attached, no video on external monitors, then going through suspend and having display work on HDMI "port 2".

Other references

One similar one I found https://old.reddit.com/r/anker/comments/12oegle/now_available_575_12in1_usbc_hub/k7uk79n/ from a year ago, although the error message doesnt fit my logs. Many others also confirm to work under windows.

Edited by Steffen Butzer
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