This is related to the admgpu.gttsize. My laptop has the maximum amount of memory (64G) and usually gttsize is half of main memory size. I just tested with cmdline="nokaslr amdgpi.gttsize=2048" and the problem does not occur. So I did some more testing with varying gttsize and got this for the built-in GPU
08:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] (rev c5) (nokaslr is always enabeld) gttssize input behaviour 2048 GOOD 2064 GOOD 2080 SEMIBAD (i.e. noticeable input lag but not as bad as below) 3072 BAD 4096 BAD 8192 BAD 16384 BAD As the build-in GPU has ~512 VRAM there seems to be problems when gttsize > 4*VRAM so I tested for the discrete GPU with 8G of VRAM gttsize input behaviour 49152 GOOD 64000 GOOD So for the discrete GPU increasing gttsize does no reproduce the bug. Bert Karwatzki
