Re: nvme(4): some non-operational power states are broken

On Mon, Sep 23, 2024 at 11:10:15AM +0100, Warner Losh wrote:

> Does Linux have active power state management?

I didn't know there was such a thing, thanks! I tried to boot with
'pcie_aspm=off' kernel parameter and dmesg said that ASPM was
disabled, but I didn't see any difference in terms of temperature
or /sys/class/power_supply/BAT0/power_now value, they all are within
normal boundaries.

> And what's the workload?

This machine is my workstation, so I would say there is almost no
workload in terms of IO.

> What performance are you seeing?

I have no other issues with the device, except for power consumption
in states 4 and 5. After enabling APST (I patched the kernel for
this) and limiting idle transitions to state 3 this problem was
mostly resolved as well, but I think it would still be worth finding
out what is actually going on.

> And what's the reported model number? What form factor?

Model number is KXG5AZNV256G, form factor is M.2 2280. If necessary,
I can send Identify command output.

> We used these at work years ago, but in only one hw spin.

For production machines idle power consumption may not be relevant
at all, but for a laptop it's a huge difference. And that's a good
news if it's just my faulty device and no one else is having the
same problem. No additional work is needed then, which is always
great :)