So the HP 
Envy 2 in 1 I have which runs Endeavour OS is one of those Ryzen machines that uses the Sensor Fusion Hub [1022:15e4] to rotate. This sensor fusion hub has been around since the first mobile Ryzen gen and is still used in the Ryzen 5000 mobile machines, mostly convertibles. But it don't rotate.
Setting KDE's tablet mode does nothing, iio-sensor-proxy is installed but will not return anything, monitor-sensor --accel just waits infinitely. Force starting iio with systemctl and checking it shows No sensors or missing kernel drivers for the sensors. Exiting and deactivates. Modprobing pcie_mp2_amd gives FATAL: Module pcie_mp2_amd not found in directory /lib/modules/7.1.8-arch1-3 which is cool. You can also modprobe amd_sfh to no avail.
I found this totally useless archbbs thread full of dead links, and funny enough I was dual booting Windows 10 on this machine, but no amount of rebooting nor disabling Fast Boot in Windows nor entirely reinstalling EndeavourOS fixes this. A live image of Cachy OS behaves the same.
If you know anything about amd_sfh or pcie_mp2_amd I am begging you, just let me rotate my screen automatically. Or y'know, if you wanna write a patch to make it work, together. Totally.
Bugzilla thread about this gamer hardware issue
EDIT: after a bit of research I see that the Linux kernel has been fighting for its life against AMD's shitass SFH driver... For over six years...
Real gamers run as root 24/7
Ok so device as you know exists:
[ 1.144670] pcie_mp2_amd 0000:04:00.7: enabling device (0000 -> 0002)
Fails to communicate with device says its not enabled?:
[ 41.148934] pcie_mp2_amd 0000:04:00.7: Failed to discover, sensors not enabled is 0
Don't see anything from amd_sfh itself so it fails at the lower level call maybe amd_sfh doesnt run until pcie_mp2_amd is working
Last things I can think of is maybe it needs to be enabled at boot to initialise? Could try writing it to the boot config
echo "options amd_sfh_hid sensor_mask=1" | sudo tee /etc/modprobe.d/amd_sfh.conf
Then I guess could try
Otherwise im fresh out of ideas
Shit looks like its broken on windows as well I wouldn't be surprised if the firmware itself is wank. Does it need to be flipped over to the other side to enable the sensor? https://h30434.www3.hp.com/t5/Notebook-Hardware-and-Upgrade-Questions/Accelerometer-stuck-in-tablet-mode-HP-envy-x360/m-p/9568251/highlight/true#M800826#1
Whelp this has been fun, hope you learned some stuff about compiling kernels
now I leave you with a shitpost as I go back to EverQuest
Sweaty the problem is ur trying to install linux on an xbox360, it only runs windows!
Sensor has no toggle in bios, I did check. I think I'm running the newest bios but I can check that too.
Writing that echo stuff to boot is done by editing the startup options at systemd-boot or whatever, right? (Edit: I see now those are terminal commands) Fwiw the tablet stuff did work in Windows 10 once upon a time.
I fuckin love the HP forums lmao.
Thank you for walking through this with me, it's actually the first time I've ever built a kernel and it rocks. Much appreciated, enjoy Everquesting lol.
Also https://consolemods.org/wiki/Xbox_360:Linux
gottem