Bug 1464204

Summary: Displays fail to wake up when booting machine away from Display Port KVM switch
Product: Red Hat Enterprise Linux 7 Reporter: Dhruv Thakkar <dhruv.a.thakkar>
Component: xorg-x11-drv-nouveauAssignee: Ben Skeggs <bskeggs>
Status: CLOSED WONTFIX QA Contact: Desktop QE <desktop-qa-list>
Severity: high Docs Contact:
Priority: unspecified    
Version: 7.3   
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: If docs needed, set a value
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Last Closed: 2021-01-15 07:38:50 UTC Type: Bug
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
Xorg.0.log
none
/var/log/messages
none
xorg.conf for nouveau drivers none

Description Dhruv Thakkar 2017-06-22 16:08:20 UTC
Created attachment 1290764 [details]
Xorg.0.log

Description of problem:

We are trying to solve an issue in which displays fail to wake up when booting a Rhel 7.3 machine (Machine A) connected to a Display Port KVM while the KVM is pointing to Machine B. The unusual bit is that xorg logs in /var/log/Xorg.0.log indicate that everything comes up correctly, and a "ps -ef |grep X|xinit" shows that X and xinit are up and running. If we boot Machine A while the KVM is pointing to it, the displays come up with no issues.

We have KMS parameters set to force the output of the video (video=DP-1:2560x1600D and video=DP-2:2560x1600D) as well as options to load the EDID information. These parameters have worked in the past for us when we used DVI connections through KVMs, but DisplayPort is not showing the same results. Note that we have additional kernel options added for extra debug information (log_buf_len=8M nouveau.debug=disp=trace,i2c=trace,bios=trace)

Using Xrandr and Udev rules with a script allow us to turn off and then back on the displays automatically, allowing us a workaround, but it still does not solve the core issue of that nouveau is not waking up the monitors.

Please see the attached logs/config files and diagram below for more information.

|Machine A| |Machine B|
\               /
 \             /
  \ _________ /
   |DPort KVM|
   |_________|
   /         \
  /           \
 /             \
|Monitor 2| |Monitor 1|


Version-Release number of selected component (if applicable):

Comment 2 Dhruv Thakkar 2017-06-22 16:09:33 UTC
Created attachment 1290765 [details]
/var/log/messages

Comment 3 Dhruv Thakkar 2017-06-22 16:10:10 UTC
Created attachment 1290766 [details]
xorg.conf for nouveau drivers

Comment 5 RHEL Program Management 2021-01-15 07:38:50 UTC
After evaluating this issue, there are no plans to address it further or fix it in an upcoming release.  Therefore, it is being closed.  If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.