Happy Saturday! Right before my next bit of overseas travel, I now have a laptop that boots successfully. Reading various support threads, Windows users are having a terrible time with this model laptop, with lockups under load, black, blue or white screens, screen corruption, colour bleeding and absolutely naff-all support from HP.  Users of the slightly more recently-released Acer/Ryzen 5 laptop aren't much better off.
Seems that the curse of AMD drivers hasn't quite lifted yet.
HP ENVY x360 Convertible 15-bq1xx/83C6, BIOS F.13 11/10/2017
What's new:
Kernel - switched to Dave Airlie's drm-next git sources. This is based on a slight downgrade to 4.15-rc8, but with all the  upstream stuff that'll appear in 4.16, in a couple of months.
Mesa/LLVM/Clang - 18.0_rc3, LLVM6, Clang v6 as in the earlier screenshot - this is the absolute bare minimum to get a usable "raven" chipset working.  Yes, you can get some love with Mesa 17.3, but it's not good. I've just noticed that I now have LLVM7 in the tree, so will rebuild Mesa against that.
I haven't checked what the changed sources have done to performance.  Feels like a slight regression, but I didn't keep detailed notes before. I'm just happy the damn thing boots.
What's not working:
- The touchscreen and pen
 
- Accelerometer (for screen orientation)
 
- The F5 key (screen backlight) isn't registering an event, so I can't do fancy automatic backlight stuff. Responds to manual activation though.
 
- Suspend/hibernate/resume - still down to the graphics drivers on this, they don't work quite the same as older Radeons and aren't going to sleep. Result: computer has no screen, no response to sysrq.
 
- Rather bizarrely, my old JMicron USB to SATA/PATA bridge isn't properly registering. I'm pretty sure I've built the right module... will check against another laptop.
 
Not tested:
- HDMI and HDMI audio - EDIT: works fine, sound and vision 

 
- SD Card reader
 
- Secure boot / TPM - other people have posted logs showing that this will work, but I can't be bothered.
 
Everything that isn't mentioned above works just fine.
When I have a spare moment (I'm packing for more travel right now) I'll play some GAMES 
 
 