I’ve been continuing to test this issue with Firefox 131, 132 and now 133 and the issue is still there all the while using KDE Plasma 6.1.4 which later upgraded to 6.1.5
So, Gentoo today has just released KDE Plasma 6.2.4 stable ( I didn’t install the testing ).
I thought I give Firefox 133 a try, and it’s looking like the issue is gone ( so far )… but as said before, was there with KDE Plasma 6.1.5
So maybe there isn’t anything wrong with Firefox but KDE’s wayland implementation ( kwin_wayland? ) was giving the wrong info to Firefox
I’ll continue to keep an eye on this, but so far, never seen so many “0%” on amdgpu_top for so long, nice to see when system is idle
I still see the high usage though when Firefox is waiting for data to arrive
KDE Plasma 6.2.4 is noticeably lower cpu usage too