Timur Kristóf of Valve’s Linux graphics driver team is the one that worked on improving the old AMD Radeon GCN 1.0/1.1 graphics card support by making AMDGPU driver improvements so it could become the default for these Southern Islands and Sea Islands GPUs rather than the legacy Radeon kernel driver. That meant better performance, RADV Vulkan support out-of-the-box, and other benefits. More recently he finished AMDGPU improvements for Kaveri and other GCN 1.1 era APUs. Now Timur’s out with some more fixes for helping select GCN 1.0 hardware.
The latest work by Timur Kristóf is on more Southern Islands (GCN 1.0) fixes for AMDGPU with a particular focus on enabling Radeon HD 7870 XT support under Linux. The Radeon HD 7870 XT is a rare breed that has never worked with the open-source Linux graphics drivers at all.
Due to Radeon HD 7870 XT GPUs having been “harvested” from more premium models that were then cut-down to HD 7870 XT specifications, the AMDGPU kernel driver hasn’t properly supported such configurations. The issue was AMDGPU needing changes to properly handling hardware with the TCC cache configuration being partially disabled/fused-off and to then make use of the remaining TCCs more optimally.
Going all the way back to 2013 was this bug report over the graphics block on this Sapphire Radeon HD 7870 XT “Tahiti LE” failing to work properly.
Another user in 2023 reported a similar bug report with the Radeon HD 7870 XT also not working under Linux at all. Finally in the past six months Timur Kristóf began poking at the issue and realizing the AMDGPU driver issues in not properly handling such “harvested” GPU configurations.
So finally with this patch series is enabling the Radeon HD 7870 XT to properly work under Linux nearly 14 years after the graphics cards first shipped.