default or selected kernelversion does not have config value CONFIG_DRM_MGAG200_IOBURST_WORKAROUND.
Result is shown for kernelversion 6.9.9

Disable buffer caching

configname: CONFIG_DRM_MGAG200_IOBURST_WORKAROUND

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Disable buffer caching
In linux kernel since version 4.19.314 (release Date: 2024-05-17)  
Enable a workaround to avoid I/O bursts within the mgag200 driver at
the expense of overall display performance.
It restores the <v5.10 behavior, by mapping the framebuffer in system
RAM as Write-Combining, and flushing the cache after each write.
This is only useful on x86_64 if you want to run processes with
deterministic latency.
If unsure, say N.