Created attachment 143950 [details]
lspci -vvv output for HP Spectre 360x

My HP Spectre x360 laptop bought in March 2019 comes with KabyLake G HD
Graphics 630 and a discrete AMD Radeon RX Vega M GL GPU.

I only enable the Radeon GPU when needed to play graphics intensive games with
`DRI_PRIME=1`, and so far I experience a lot of GPU deadlocks with the
following symptoms:
- Temperatures raise, the CPUs are throttled. Framerate drops when this
happens.
- Later on, GPU faults are reported in dmesg, the game's rendering freezes (but
music continues playing). I am still able to alt+tab back to desktop or open a
terminal, but the game's process can't be killed. If I'm monitoring
temperatures, lm_sensors always reports a bogus 511°C temperature for the AMD
dGPU at this point, before breaking.
- Any subsequent attempt at using the AMD GPU will cause a system deadlock, and
I need to force shutdown with the power button.

My testing so far has covered:
- Unity3D games like For The King or StarCrawlers. The crash happens mid-game,
not in a strictly reproducible manner, but seems related to CPU
temperature/throttling.
  * I could also reproduce the crash with SuperTuxKart, not in-game but when
alt-tabbing back to desktop.
  * I could not get the crash yet with glmark2. With For The King, I can
reliably get a crash within 1 to 10 minutes in-game when playing with "High" or
"Dream" graphics quality.
- Kernel 5.0.x (up to 5.0.7) from Mageia 7 (Cauldron), e.g.
5.0.7-desktop-4.mga7.
  * I also tried `git://people.freedesktop.org/~agd5f/linux -b
amd-staging-drm-next` at b07c394a327fc9e435ee03288584c111fa73d963, but I still
got the same symptoms. dmesg output was in part different though, more spammy.
  * Following discussions in bug 109692, I tried the patches provided by Andrey
Grodzovsky in bug 109692 comment 34, but they did not solve the issue for me.
- Mesa 19.0.0 to 19.0.2 built against LLVM 7.0.1.
- Suspecting the CPU temperature/throttling as a trigger, I'm using
https://github.com/kitsunyan/intel-undervolt to undervolt the CPU Cache by -100
mV and set the CPU limit temperature to 80°C instead of 100°C. This has helped
with throttling issues I had during code compilation, but no visible change on
my GPU crashes that I can tell. I can disable this undervolting when doing
tests if required.

I found various bug reports which might well be duplicates, but I'm opening my
own to avoid hijacking discussions on what may or may not be the same root
cause: bug 109461, bug 109466, bug 109692 (I installed Shadow of the Tomb
Raider but haven't checked if I can reproduce this one's symptoms yet), bug
109819.

I attach some relevant logs on the system and the bug. Please ask for anything
else you may need.