Back in 2020 AMD started working on a FreeSync video mode optimization . Enabling the option added additional mode-setting modes common to video frame rates and refresh rates adjusted for the VRR capability of the attached display. Ultimately the "freesync_video" mode adjusts the front porch timing to strive for a seamless mode change experience.
AMD got the feature all set last year. While this should lead to a better video playback experience for those with a FreeSync monitor, there is the possibility of higher power consumption when enabled. Originally this was intended to be a temporary solution until a long-term solution is sorted out for any user-space interface changes to imrove the Linux user experience around video playback on variable rate refresh displays.
Up to now enabling the feature required using the amdgpu.freesync_video=1 module parameter. With Linux 5.18 though that freesync_video option is being dropped with this FreeSync Video Mode now being used by default.
AMDGPU for Linux 5.18 also has clean-ups to its power management code, improved RAS code, SR-IOV fixes, improved vRAM access for debugging using SDMA, TLB flushing fixes for Arcturus / Vega20, DisplayPort tunneling fixes, support for enabling both SMU i2c buses where supported, suspend-to-idle (s2idle) improvements, and more.
Meanwhile the AMDKFD compute driver with this pull request is merging the CRIU checkpoint/restore capabilities that is improving for their ROCm stack and the big supercomputing / HPC customers .
The full list of initial AMDGPU/AMDKFD kernel driver feature changes building up for Linux 5.18 can be found via this pull request . Hopefully in the next month or two we begin seeing AMDGPU RDNA3 kernel patches if AMD is indeed planning for their next-generation cards in H2'2022 and wanting to have good out-of-the-box Linux support at launch given the alignment of kernel cycles and distributions.