Created =
attachment 133068 [details]
The script used to reproduce the error.
As I attempted to hotplug my R9 290 for a VM gaming setup, I stumbled on th=
is
issue.
The main kern.log error to come up is:
> [ 160.013733] [drm:ci_dpm_enable [amdgpu]] *ERR=
OR* ci_start_dpm failed
> [ 160.014134] [drm:amdgpu_device_init [amdgpu]] *ERROR* hw_init of IP=
block <amdgpu_powerplay> failed -22
> [ 160.014531] amdgpu 0000:01:00.0: amdgpu_init failed
For my setup I use a Kaby Lake iGPU running i915.
With the R9 290 using vfio-pci / amdgpu.
Ubuntu 17.04 (4.10.0-28-generic).
Mesa 17.1.4 from the padoka stable PPA.
I'm able to reproduce this as follows.
1. Boot with vfio-pci capturing the card and amdgpu blacklisted. Kernel fla=
gs:
> intel_iommu=3Don iommu=3Dpt vfio-pci.ids=3D1002:=
67b1,1002:aac8
2. Since I run Gnome3 on Ubuntu 17.04, this will bring me to a wayland gree=
ter
which uses my iGPU. Drop to a free TTY, without logging in. This prevents X=
org
from responding to the AMD card becoming available.
3. Run the attached script "rebind-amd.sh" as root to bind back a=
nd forth
between vfio-pci and amdgpu in an infinite loop.
This will:
A. modprobe both drivers to be sure they're loaded.
B. Print information about the driver and card usage.
C. Use the new_id > unbind > bind > remove_id sequence to switch d=
rivers.
What happens is:
vfio-pci -> vfio-pci, Gives no problems, of course.
vfio-pci -> amdgpu, This works and the amdgpu driver initializes the car=
d.
Attached monitor(s) start searching for signals.
amdgpu -> vfio-pci, Since no Xorg is using the dGPU this works without
problems.
vfio-pci -> amdgpu, Fails to initialize dGPU with the kernel error above.
I've attached the script, the output of the script and the full kern.log.