Ryzen 7900 iGPU stuck at max clock after pve-firmware 3.18-6

HellYeah1994

Member
Nov 19, 2022
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Hi all,

after a routine apt full-upgrade, the Raphael iGPU on a testing PVE node stopped clocking down at idle. It now sits permanently at the highest DPM state (2200 MHz instead of 600 MHz), which costs roughly 7–9 W

Idle behaviour of the iGPU before and after the upgrade:

pve-firmware 3.18-5pve-firmware 3.18-6
pp_dpm_sclk (idle)600 MHz2200 MHz (pinned)
vddgfx0.750–0.770 V0.969 V
gpu_busy_percent0 %5–26 %
CPU package power (PPT)25–27 W30–36 W


The decisive detail is gpu_busy_percent: with 3.18-6 the GPU reports 5–26 % utilisation while the fence counters show exactly one GFX job since boot - there is no work at all. The SMU apparently honours that bogus utilisation reading and keeps the clock pinned at maximum. With 3.18-5 the same idle system correctly reports 0 % and drops to 600 MHz.

Note that the reported utilisation does not correlate with actual power draw (from gpu_metrics): at "5 %" the GPU drew anywhere between 4.8 W and 17.4 W, at "26 %" as little as 5.6 W.

Kernel log confirms the firmware change:
before: Found VCN firmware ... Revision: 15 / DMUB firmware version=0x05003000
after: Found VCN firmware ... Revision: 21 / DMUB firmware version=0x05003300

Does anyone else have similar symptoms?

Happy to provide further data if useful.