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

On Mon, Sep 23, 2024, 10:41 AM Alexey Sukhoguzov <mail@eseipi.net> wrote:

> Hi,
>
> My NVMe controller is Toshiba XG5, and it has 6 power states: the
> first three (0-2) are normal and the last three (3-5) are NOPS.
> Here is 'nvmecontrol power -l nvme0' output:
>
>  #   Max pwr  Enter Lat  Exit Lat RT RL WT WL Idle Pwr  Act Pwr Workloadd
> --  --------  --------- --------- -- -- -- -- -------- -------- --
>  0:  8.0000W    0.000ms   0.000ms  0  0  0  0  0.0000W  0.0000W 0
>  1:  3.9000W    0.000ms   0.000ms  1  1  1  1  0.0000W  0.0000W 0
>  2:  2.0000W    0.000ms   0.000ms  2  2  2  2  0.0000W  0.0000W 0
>  3:  0.0500W*   1.500ms   1.500ms  3  3  3  3  0.0000W  0.0000W 0
>  4:  0.0050W*   6.000ms  14.000ms  4  4  4  4  0.0000W  0.0000W 0
>  5:  0.0030W*  50.000ms  80.000ms  5  5  5  5  0.0000W  0.0000W 0
>
> The problem is that only one of the NOPS is working as expected
> (state 3). Another two (states 4-5) skyrocket the controller's power
> consumption far beyond normal (0-2) power states do, and far beyond
> reasonable. For example, when the controller is in state 3, my
> system consumes about 3-3.5 W at idle (according to acpiconf with
> laptop power cable unplugged), in states 0-2 - about 4 W, and in
> states 4-5 consumption is approaching 6 W. Thus, the NVMe becomes
> the hottest part of the system (>50C, still idle), and it eats up
> almost half of the battery alone.
>
> Linux doesn't have this issue, so it seems to be nvme(4) related.
> All the above data is collected on 14.1-RELEASE Live USB with no
> filesystem mounted. 15-CURRENT has the same problem.
>
> Any ideas what it might be?
>

Does Linux have active power state management?

Warner


> Regards,
> Alexey
>
>