google-coral
ASPM support?
Description
I have an M.2 A+E key Coral module installed in a Lenovo M920q PC running TrueNAS, with the latest BIOS and all tuning suggestions from powertop applied.
Without the TPU installed, the PC can spend most of its time in package C-state PC8, but with the TPU present and fully idle, the PC doesn't go below C-state PC3. Simply having the TPU installed adds about 3 watts to the PC's idle power consumption. This is significantly above the datasheet 375-400mW idle power for the TPU itself, and I suspect can mostly be attributed to the PC being unable to enter lower C-states. lspci -vvv reports that the TPU supports ASPM L0s/L1 but that it's disabled, and the same appears with pcie_aspm=force on the kernel command line.
I've seen a few references to manually disabling ASPM in other bug reports, but I'm not sure if that's as a workaround for ASPM bugs in host systems or due to issues with the Coral device itself. So... is this expected to work and the issue is some kernel or BIOS misconfiguration on my side, or does the Coral just not support ASPM?
Click to expand!
Issue Type
Support
Operating System
Linux
Coral Device
M.2 Accelerator A+E
Other Devices
No response
Programming Language
Other
Relevant Log Output
No response
Same issue on a similar tiny pc, ASPM disabled causes CPU to stay in low cstate, double the idle power consumption of the host
Thought I'd add in I've got the same issue. M.2 Coral being used in Frigate in a container running on Unraid. With the TPU installed, even if Frigate isn't running, still forces the system to stay in C3. As soon as I remove the Coral I can go as low as C8 and the power consumption drops over 10W.
Would love to figure out a way to get lower than C3 and still use the Coral.
I never did. I wound up switching my Frigate setup from Coral to OpenVINO, but that's not much of a workaround 🙁
I tried to force the TPU to ASPM but this seems to break the whole system.
Do you get it done?
