Red Hat Bugzilla – Bug 1263815
Test case failure: Multihead - Large Desktop on ATI Pitcairn PRO [Radeon HD 7850] [1002:6819]
Last modified: 2017-07-25 17:36:06 EDT
Created attachment 1074176 [details] Xorg log of problem Filed from caserun (https://tcms.engineering.redhat.com/run/260129/#caserun_10820258) Version-Release number of selected component (if applicable): RHEL-7.2-20150820.0 xorg-x11-server-Xorg-1.17.2-7.el7.x86_64 xorg-x11-drv-ati-7.5.0-3.el7.x86_64 kernel-3.10.0-306.0.1.el7.x86_64 linux-firmware-20150727-41.git75cc3ef.el7.noarch mesa-dri-drivers-10.6.0-1.20150616.el7.x86_64 Steps to Reproduce: 1. obtain a card that is capable to connect 4 screens and 4 monitors 2. plug everything together and start GNOME 1. go into Control Center -> Display 2. Create 4x1 setup with all displays set to the same resolution 3. Create 2x2 setup 4. Create 1x4 setup with all displays set to different resolution Actual results: If monitors are hotplugged up to 4 (DP must be present on boot due to another bug[1]) then 2/4 monitors work and the other two are registered by xrandr and mode is set, but monitor gets no signal and goes to sleep. If all four are plugged on boot, then 0/4 monitors work - they all get registered by xrandr and modes set, but no signal goes to the monitors and they all go to sleep. Expected results: you should be able to move cursor from one screen to another flawlessly in all setups. In different resolution setup there should be borders where you cannot pass to another screen accordingly Additional info: Xorg log attached is from latter scenario (all 4 screens plugged at boot time)
What kind of monitor configuration was this tested with? There was a bug previously in xf86-video-ati where if we failed to do a modeset due to hardware limitations we'd drop all of the displays that had been working previously, which sounds like what you might be seeing here