• Yet Another Fix Coming For Older AMD GPUs On Linux - Thanks To Valve Developer Timur Kristóf of Valve’s open-source Linux graphics driver team has been doing a fantastic job enhancing the older AMD Radeon GPU support under Linux. • Last year he made enough improvements to the AMDGPU open-source driver that older Radeon GCN 1.0/1.1 dGPUs switched over to AMDGPU by default for nice performance gains, RADV Vulkan driver support out of the box, and all around better experience than using the legacy Radeon driver. • He’s also been fixing countless bugs affecting older AMD GPUs. • There is another improvement on the way for benefiting some with aging AMD GPUs. • Since June 2024 there has been a bug report over AMDGPU issues when trying to use a Radeon R9 M380 graphics processor within an iMac under Linux. • Loading the AMDGPU driver with the Radeon GPU in this aging Intel-powered iMac would resort in issues at boot and kernel errors around the AtomBIOS and various errors, for example: This issue was also reported by another user more recently and it was also noted that if using the legacy Radeon kernel driver it would work out fine.
Article Summaries:
- Valve’s open‑source graphics team has added a new fix for older AMD Radeon GPUs on Linux. After a year‑long bug report, Timur Kristóf identified that the AMDGPU driver fails on Sea Islands (GCN 1.1) cards such as the R9 M380 in Intel‑powered iMacs because the driver does not apply the correct voltage to the display clock when memory‑clock dynamic power management (MCLK DPM) is enabled. His patch disables MCLK DPM and forces the highest memory clock, eliminating boot‑time kernel errors. The changes are in a Git branch and will be reviewed for upstream inclusion, extending reliable Linux support to decade‑old Apple iMacs.
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