polaris powerplay init fails: There must be 1 or more PCIE levels defined in PPTable

Submitted by Shawn Anastasio

Assigned to Default DRI bug account

Link to original bug (#107518)

Description

Created attachment 141002
dmesg for 4.17.11-200

When booting kernel 4.17 or 4.18-rc8+ (git) on a POWER9 system with an ASUS Rx 580 GPU, the following messages are printed to the kernel log:

[ 10.398837] amdgpu: [powerplay] There must be 1 or more PCIE levels defined in PPTable.
[ 10.398839] amdgpu: [powerplay] Failed to populate SCLK during PopulateNewDPMClocksStates Function!
[ 10.398840] amdgpu: [powerplay] Failed to populate and upload SCLK MCLK DPM levels!


Note that the system is booted with the kernel argument amdgpu.dc=0 to work around this issue: https://bugs.freedesktop.org/show_bug.cgi?id=107049

GPU performance seems to be significantly hindered as a result of these errors.

Booting with amdgpu.dpm=0 silences the errors but does not improve performance.

Attachment 141002, "dmesg for 4.17.11-200":
log_4_17_11-200.txt