AMDGPU/Radeon For Linux 4.5 Drops UMS Support, Brings Optimizations

[SystemCrasher]

No major differences. Same clocks and voltages uses in both cases. The main difference is the programming sequences and the interactions with other modules (e.g., displays, multi-media, etc.).

Hmm, ok I managed to remember one power management related difference myself. Someone using amdgpu told it seems to lack PWM fan control so far, but PWM fan control works okay in Radeon driver (for GCNs, older GPUs lack it, even if I can remember some patches for something like 68xx in bug tracker, but not sure of their fate). Not sure if it still a case though, I haven't yet got some of newer GCNs to give AMDGPU a try.

[agd5f]

Hmm, ok I managed to remember one power management related difference myself. Someone using amdgpu told it seems to lack PWM fan control so far, but PWM fan control works okay in Radeon driver (for GCNs, older GPUs lack it, even if I can remember some patches for something like 68xx in bug tracker, but not sure of their fate). Not sure if it still a case though, I haven't yet got some of newer GCNs to give AMDGPU a try.

There is pwm fan control in amdgpu.

[SystemCrasher]

There is pwm fan control in amdgpu.

Is it working now? I do not have GPUs supported by AMDGPU so far, so I can't check it myself, sorry. Recently someone attempted to take manual fan control using AMDGPU, since it exposed PWM just like Radeon does. Yet, it failed, while the same thing working fine in Radeon for GCNs and I can manually control PWM, if desired. Code paths were looking quite similar, but at the end of day it appeared like if AMDGPU exposes PWM, but haven't implemented manual fan control so far. Has it been fixed recently, or I miss something? Or it just works in different way?

[agd5f]

It works the same way as radeon. It was not fully implemented in the initial powerplay patches, but has since been finished.