Since the upgrade to 5.15.x kernels I have regular GPU hangs on my integrated Iris Xe Graphics.
Hang occurs in both the Plasma Wayland session and SDDM which is using X11.
Reverting to 5.14.18 kernel fixes the issue.
Machine: Lenovo T14 Gen2 Intel
DE: Plasma 5.23.3 (X11)
CPU: 11th Gen Intel i7-1165G7
GPU: Intel TigerLake-LP GT2 [Iris Xe Graphics]
[ 33.414165] i915 0000:00:02.0: [drm] GPU HANG: ecode 12:1:85dffffb, in plasmashell 
[ 33.415186] i915 0000:00:02.0: [drm] Resetting rcs0 for stopped heartbeat on rcs0
[ 33.415239] i915 0000:00:02.0: [drm] plasmashell context reset due to GPU hang