AMD Promotes Navi 14 Linux Support Out Of "Experimental" + Fixes For Raven Ridge
After the original Navi 12/14 open-source driver support was published, it was then marked as experimental. Under that experimental state, the hardware initialization only happens if amdgpu.exp_hw_support=1 is set as a parameter for the AMDGPU kernel driver.
But now just days away from the Linux 5.4.0 kernel release, an AMDGPU fixes pull request was sent in that removes the experimental flag for Navi 14. The commit message for the change simply states, "5.4 and newer works fine with navi14."
Navi 14 is at least in part the forthcoming Radeon RX 5500 series. With those lower-tier Navi cards shipping this quarter, it's great to see Linux 5.4 will be ready for when those retail cards (and mobile GPU) arrive.
Navi 12 meanwhile is still marked as experimental for Linux 5.4.
Other changes in this "fixes" pull request include two stability regression fixes for Raven Ridge APUs, which end up disabling S/G and GFXOFF for those Zen+Vega APUs. S/G apparently is still causing problems when IOMMU is enabled for some systems while the GFXOFF power-savings functionality still also has its own set of problems with select board/firmware combinations.