Disable GPU on i.MX8X

[Acuadros]

Hi,

We are looking to decrease the temperature on a TQMa8Xx module, based on the i.MX8X processor.

Our idea is to disable unnecessary systems like the GPU and VPU. I have tried disabling them on the device tree with this patch:

 &gpu_3d0 {
-	status = "okay";
+	status = "disabled";
 };
 
 &imx8_gpu_ss {
-	status = "okay";
+	status = "disabled";
 };
 

But I am not sure it worked, how could we check if the GPU/VPU are powered and enabled?

Also, I have found this post System Controller Firmware 101 - Power management service which points to the SCU firmware code. We can modify the SCU, but I am not sure which files or lines need to be modified to disable the power on the GPU.

Best regards,

Antonio Cuadros.

[b36401]

GPU automatically goes in power mode off when nothing is redrawn on screen. So there is no need to do it manually.

By the way you can check GPU status with via its sysfs entry:

# cat /sys/kernel/debug/gc/idle
Start: 5217156788 ns
End: 28642408610 ns
On: 21105480 ns
Off: 22775044156 ns
Idle: 0 ns
Suspend: 629102186 ns