Renoir fails to enable high refresh rate mode on a monitor connected over DP MST
Brief summary of the problem:
Renoir fails to enable refresh rate that is higher than 60Hz on a 2560x1440 165Hz gaming monitor that is connected through a USB-C Docking station with a built in MST hub.
On swaywm, when attempting to run swaymsg output [output] mode 2560x1440@165Hz
, the screen turns black and the only way to get image again is to unplug the monitor from the dock and plug it in again. On X11 (i3wm), when running xrandr output [output] rate 165
, it fails silently (not even a crtc configure failed
error) and the rate stays at 60.
I am however able to switch to 120Hz if I reduce resolution to 1920x1080 first, both on sway and X11.
On both X11 and swaywm, the rate is 60 right after plugging the monitor in, but if I plug it in over a direct USB-C to DP cable (no MST involved), starts at 165Hz out of the box and doesn't have any issues changing modes.
I'll try to provide logs a bit later, but from what I've seen neither sway nor X11 log anything relevant when the issue occurs. I can try to provide drm debug logs, but they spam so much it's difficult to capture the exact moment the display is plugged in.
Also not sure if this is relevant to this issue, but Freesync does not work either through the dock (enabling it fails silently, both on X11 and sway) but works fine when the monitor is connected directly to the USB-C port.
Possibly related to #1426 (closed) and #1442.
Hardware description:
- Laptop: Lenovo ThinkPad T14 AMD (20UES00L00)
- CPU: AMD Ryzen 7 PRO 4750U
- GPU: AMD Radeon Vega 7 integrated
- System Memory: 32GB DDR4
- Display(s): Internal eDP LP140WF9-SPF1 (1920x1080 60Hz), External DP DELL S2721DGFA (2560x1440 165Hz)
- Type of Diplay Connection: DP MST through USB-C Alt mode docking station
- Docking station: Lenovo ThinkPad USB-C Gen2 docking station (40AS)
System information:
- Distro name and Version: Arch Linux rolling
- Kernel version: 5.10.11-arch
- Custom kernel: 5.11-rc5 mainline
- AMD package version: none
How to reproduce the issue:
- plug in 2560x1440 monitor to USB-C DP MST dock
- attempt to enable refresh rate higher than 60hz
Attached files:
No files attached.