https://bugs.freedesktop.org/show_bug.cgi?id=100443
--- Comment #3 from Christian Lanig freedesktop@lanig.email --- I have looked a bit around for the cause of these messages. In the first case I guess I found a reason: /*Driver went offline but SMU was still alive and contains the VFT table */ in line 340 in polaris10_smumgr.c
In case of the second message in line 575 in hwmgr.c the driver searches for the maximum leakage voltage I guess, where the virtual voltage ID can have values between 0xFF01 - 0xFF08, probably kind of representing the power states ATOM_VIRTUAL_VOLTAGE_ID0 - ATOM_VIRTUAL_VOLTAGE_ID7.
But it doesn't find the specific voltage value in the table so instead of setting the value of the *sclk destination it prints the assertion. That's kind of my interpretation. Unfortunately the rest is too intricate for me.
The messages disappeared with an R9 290X.
The RX 480-BIOS can be downloaded here: https://www.techpowerup.com/vgabios/184548/xfx-rx480-8192-160614