High Power Consumption of AMD RX6800xt in Idle with Secondary Monitor Connected

[Jaroslav Pulchart]

Dear AMD GPU Kernel Maintainers,

I am writing to report an issue with high power consumption of my AMD
RX6800xt graphics card when a secondary monitor is connected.

Upon investigation, I observed that my desktop computer generates more
heat while idling. I determined that the high power consumption issue
arises when I connect a secondary monitor to my AMD RX6800xt card,
causing it to consume approximately 40W of power in idle state .

I checked the "GFX Clocks and Power:" in
/sys/kernel/debug/dri/1/amdgpu_pm_info of my RX6800xt during idle, and
here are the findings:

With the secondary monitor connected memory frequency is up and
constantly at 1000MHz:
        1000 MHz (MCLK)
        3 MHz (SCLK)
        1825 MHz (PSTATE_SCLK)
        1000 MHz (PSTATE_MCLK)
        856 mV (VDDGFX)
        45.00 W (average SoC)

Single monitor connected:
        96 MHz (MCLK)
        0 MHz (SCLK)
        1825 MHz (PSTATE_SCLK)
        1000 MHz (PSTATE_MCLK)
        6 mV (VDDGFX)
        8.00 W (average SoC)

The significant difference in power consumption between the two states
indicates a potential issue in power management that needs to be
addressed. Your assistance in resolving this matter would be greatly
appreciated.

Thank you for your attention to this issue.

Best regards,
Jaroslav Pulchart