https://bugs.freedesktop.org/show_bug.cgi?id=109887
--- Comment #7 from hagar-dunor hagar-dunor@wanadoo.fr --- Met the same annoyance, and found a rather convoluted way to get around it. It would be better overclocking/undervolting work by setting pp_od_clk_voltage only.
https://forum.level1techs.com/t/how-to-overclock-vega-on-linux/132771/65