Bug 88773

Summary: X crashes when using a zaphod config while more than two GPUs are present.
Product: xorg Reporter: MichaelLong <harn-solo>
Component: Server/GeneralAssignee: Xorg Project Team <xorg-team>
Status: RESOLVED MOVED QA Contact: Xorg Project Team <xorg-team>
Severity: major    
Priority: medium    
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.0.log with backtrace
none
Attempt to create a more meaningful backtrace with gdb.
none
Zaphod head mode xorg.conf file. none

Description MichaelLong 2015-01-24 12:08:16 UTC 
Created attachment 112775 [details]
Xorg.0.log with backtrace

My desktop system is configured to use a simple zaphod head configuration, first head is dedicated to my monitor, the second head is a TV. The config is bound to an AMD Radeon HD 5430 card.

I'm also operating vga-passthrough VMs by using KVM/qemu on that system.

A second GPU (GeForce GTX 980) is mainly dedicated for this purpose. There are NO related nouveau/NVIDIA kernel and X components (DDX, mesa etc. ) installed.

So far this setup works great.

Now when I install a third GPU, no matter it is an additional NVIDIA based or AMD based GPU, the X Server instance crashes. 

(Side note: AMD based GPUs are stubbed out with pci-stub using the kernel command line to make sure those cards are not picked up by X accidentally).

I noticed this behavior only when using a zaphod config, removing any xorg configs everthing is working.

Kernel: 3.18.x
X.Org X Server: 1.15.2
Comment 1 MichaelLong 2015-01-24 12:09:56 UTC 
Created attachment 112776 [details]
Attempt to create a more meaningful backtrace with gdb.
Comment 2 MichaelLong 2015-01-24 12:11:13 UTC 
Created attachment 112777 [details]
Zaphod head mode xorg.conf file.
Comment 3 GitLab Migration User 2018-12-13 22:31:29 UTC 
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/xorg/xserver/issues/468.

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.