Comment 1 for bug 1981883

This crash occurs after also firing several warnings with backtraces -

[ 318.108644] WARNING: CPU: 6 PID: 13667 at drivers/gpu/drm/drm_crtc_helper.c:221 drm_helper_disable_unused_functions+0x32/0x50 [drm_kms_helper]

[ 318.109727] WARNING: CPU: 6 PID: 13667 at drivers/gpu/drm/drm_crtc_helper.c:101 drm_helper_encoder_in_use+0x4d/0xe0 [drm_kms_helper]

[ 318.110742] WARNING: CPU: 6 PID: 13667 at drivers/gpu/drm/drm_crtc_helper.c:141 drm_helper_crtc_in_use+0x3c/0xb0 [drm_kms_helper]

All of these warnings are the same code check, which warns when the driver reports atomic modesetting but calls legacy modesetting functions. Beyond that summary, I am way out of my depth, and someone from AMD will probably have to untangle this for 5.15 (later in 5.17 this entire custom fbdev implementation was removed and replaced with common code).