[Bug 220110] probably thunderbolt or pci leads to pci usage counter underflow

[Bjorn Helgaas]

>From Denis's report at https://bugzilla.kernel.org/show_bug.cgi?id=220110:

> I am having problems with my laptop that has a thunderbolt
> controller to which I connected an AMD 6750XT.
> 
> The topology of my system is described in this bug:
> https://gitlab.freedesktop.org/drm/amd/-/issues/4014 yet I don't
> know if this is related or not.
> 
> I experienced PC attempting to enter s2idle while playing a YT
> video; PC has become totally unresponsive to input in any
> keyboard/mouse and power button after turning off screens attached
> to the AMD card (the built-in screen was off already).
> 
> From a look at the logs it appears one uncorrectible AER pci error
> triggered a pci root reset, and that comes with a bug where the
> usage counter assumes a wrong value; this in turn seems to cause all
> sorts of weird bugs.
> 
> That however is my interpretation of the attached log, that might be
> very wrong.
> 
> This is the first time I experience this bug in a year with this
> laptop and I don't know how easy it is to reproduce.
> 
> The kernel has been compiled from sources and it has
>
>   [PATCH v2] PCI: Explicitly put devices into D0 when initializing
>   [PATCH v4] PCI/PM: Put devices to low power state on shutdown
> 
> as I am helping testing things. I find unlikely any of those might
> cause these issues especially "PCI: Explicitly put devices into D0
> when initializing" that has been there for a few weeks now.
> 
> Thanks in advice to whoever will help me.