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

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?

Regards,
Alexey