Hello Raphael,

For almost two years now, I've been trying to get patches from Ubuntu that
enable ASPM for devices behind Intel's VMD, necessary to get full lower-power
states (including very-reduced power usage during s0ix sleep) on my Alderlake
(et al.) laptop, upstreamed into mainline.

One such thread: https://lore.kernel.org/linux-pm/218aa81f-9c6-5929-578d-8dc15f83dd48@panix.com/

Since the original set of patches on this, most of the work has been pushed
upstream, with only this last patch required to get fully into the "CPU%LPI"
and "SYS%LPI" (names according to "turbostat") states.

I'm surprised that with the number of VMD-enabled laptops out there (which I
had to keep on so I could dual-boot into Win11 (the disk geometry changes if
I disable it, rendering the Win11 partition useless)), that there haven't been
many reports of excessive power usage in Linux during sleep; perhaps because
many installations are running stock Ubuntu kernels (where I assume variants
of this patch remain) it isn't an issue, but I do believe having this upstreamed
is still valuable.

I don't have the resources you've got to test this fully for regressions, nor
the expertise getting a patch into the kernel, so I'd like to again bring this
up for discussion (hence the phone-book of a CC: here).

If there's anything I can do to help get this done, please let me know.

Thank you,

-Kenneth Crudup

-- 
Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange County CA