[PATCH] nvme-pci: Add sleep quirk for Kingston drives

[Georg Gottleuber]

Am 06.12.23 um 10:24 schrieb Christoph Hellwig:
> What does save a lot of power mean, and why does it only apply to
> some platforms?  I suspect the more likely case is that APST is
> simply completely broken on this device?

Hello,

power consumption in s0ix varies depending on mainboard and NVMe SSD. 
Some examples:
Board,           nvme(id), mW w/o patch, mW with patch, kernel
NS5X_SN7XAU,     0x500f,   2691mW,       487mW,         6.2.0
NS5X_SN7XAU,     0x2263,   2262mW,       741mW,         6.2.0
PH4PRX1_PH6PRX1, 0x2263,   3042mW,       760mW,         6.2.0
NS5X_SN7XPU,     0x500f,   3135mW,       779mW,         6.5.0

All measurements were taken with the battery disconnected and a
modified adapter plug.

I don't have a deeper insight into APST to judge whether something is 
not working. But all other NVMe SSDs we have tested sleep with a power 
consumption below 2W (Samsung 970 Evo, Samsung 980, Corsair MP600 PRO 
NH, other Kingston NV1 with ID != 0x500f).

We originally noticed that newer Kingston NV1 (with id 500f) led to 
higher standby consumption. With some trial and error I came to the 
conclusion that the problem lies with 'Simple Suspend'.

Kind regards,

Georg Gottleuber