[amdgpu/DisplayPort] KDE Wayland session is segfaulting right after login

Submitted by Shmerl @shmerl

Assigned to Default DRI bug account

Link to original bug (#107213)

Description

I just tried to use a Wayland session with KDE Plasma 5.13.2 (Debian testing) and it's segfaulting right after login and falling back to sddm.

That's what I see in dmesg:

[ 176.359816] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:956
[ 176.814144] QThread[2620]: segfault at f ip 00007f30f30b0e60 sp 00007f30e506e4f0 error 4 in libwayland-client.so.0.3.0[7f30f30a9000+d000]

Not sure whether it's amdgpu problem of something with KWin.

GPU: AMD Vega 56, connected over DisplayPort.

OpenGL renderer string: Radeon RX Vega (VEGA10, DRM 3.25.0, 4.17.0-1-amd64, LLVM 6.0.1)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.1.3

Corresponding KDE bug: https://bugs.kde.org/show_bug.cgi?id=396066