Displays behind MST Hub don't work anymore after Standby
Thanks for the S3 Standby and MST Patches which landed into the Linux Kernel. They already improved a lot of things!
I noticed that despite MST now working again after plugging it in, it unfortunately seems to stop working after a Standby session.
Hardware description: ThinkPad T14s Gen 2a
- CPU:
AMD Ryzen 7 PRO 5850U with Radeon Graphics - System Memory:
32GB - Display: Built-in Display (1920x1080) + 2x Dell 27" (3840x2160) + 1x AOC 23" (1920x1080)
- Type of Display Connection: eDP + 2x DP (Behind MST) + 1x HDMI (Behind MST)
System information:
- Distro name and Version: Arch Linux
- Kernel version:
master - c96618275234ad03d44eafe9f8844305bb44fda4 - Custom kernel: -
- AMD official driver version: -
How to reproduce the issue:
- Turn on computer
- Plug in MST Dock
- All three screens behind the MST Dock work + internal display is also working
- Enter standby
- Exit standby
- Computer wakes up, still reports all four screens connected, but just the internal display is working
This can be reproduced on S3 and S0ix. It seems like something crashes in the amdgpu driver while entering standby.