Created attachment 80547 [details]
pci_restore_config_dword debugging when resuming with dGPU off at suspend

It is log output like this that worries my about the 0xff reads from the pci
config space.

I set this in dynamic_debug:

drivers/pci/pci.c:964 [pci]pci_restore_config_dword =p "restoring config space
at offset %#x (was %#x, writing %#x)\012"

Then it gives this 0xff writing to the pci address space on restore when using
the integrated gpu.  Surely this cannot help.  My guess is that the hardware
should be removed from the kernel when the power is turned off.  But that's
just a hunch.