I have an x92 box with Amlogic Meson GXM (S912). The SOC has a Mali-T820 GPU, and the box has 2 GB of RAM and 16 GB of eMMC. I'm running Armbian 25.11.2 noble on it. While using the Wayfire Wayland GUI, there is a lot of kernel output like this, constantly repeating:

 

panfrost d00c0000.gpu: shader power transition timeout
panfrost d00c0000.gpu: tiler power transition timeout
panfrost d00c0000.gpu: l2 power transition timeout

 

The GUI works, and hardware 3D acceleration works. But it would be nice to get this spam out of the logs, and I also wonder if there is really some problem. Like, maybe the kernel doesn't know how to change GPU voltages. Maybe it is related to this at boot, maybe due to an issue with the device tree. 

 

kernel: panfrost d00c0000.gpu: error -ENODEV: _opp_set_regulators: no regulator (mali) found

 

The only other sign of something being possibly wrong is that SOC temperature goes surprisingly high when playing hardware accelerated video. That ought to be energy efficient. I'm running Mopidy and Firefox at 53°C and just playing a video can get it to 70°C.

 

It is possible to make these errors go away via:

 

echo on | sudo tee  /sys/bus/platform/devices/d00c0000.gpu/power/control

 

I don't know if changing that from auto to on will increase power consumption. Alternatively I tried to add a dummy regulator to the device tree and set mali-supply of the GPU to that regulator. Adding the dummy regulator only removes this single error at boot time:

 

panfrost d00c0000.gpu: error -ENODEV: _opp_set_regulators: no regulator (mali) found

 

The power domain picture of the S912 datasheet shows a VDD_EE (Everything Else) input to the chip from an external PMIC, and then 3 components in the GPU, each with individual switches to VDD_EE. The 3 components are: GP0+L2C_0, PP0+L2C_1 and PP1. I suppose they correspond to the 3 types of power timeout errors, though I'm not sure which is which. This seems to show that there is no possibility for voltage scaling for individual GPU parts or even the whole GPU, without actually changing VDD_EE and everything else it powers. So, probably all the GPU driver needs to know is how to flip those three switches.

Edited January 28Jan 28 by dreamlayers
Technical explanation of power domain problem

There is no gpu support in these amlogic tvbox builds.   

28 minutes ago, SteeMan said:

There is no gpu support in these amlogic tvbox builds.

What does that mean? Panfrost is the GPU driver, for the Mali-T820 GPU. I have hardware acceleration for 3D graphics and video playback, in Armbian.

Edited January 28Jan 28 by dreamlayers

What exact image are you running? Or better yet providing full logs with armbianmonitor -u