Nouveau - Jun 2017 - [Bug 101559] New: Displays fail to wake up when booting machine away from Display Port KVM switch

https://bugs.freedesktop.org/show_bug.cgi?id=101559

            Bug ID: 101559
           Summary: Displays fail to wake up when booting machine away
                    from Display Port KVM switch
           Product: xorg
           Version: unspecified
          Hardware: x86-64 (AMD64)
                OS: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Driver/nouveau
          Assignee: nouveau at lists.freedesktop.org
          Reporter: dhruv.a.thakkar at leidos.com
        QA Contact: xorg-team at lists.x.org

Created attachment 132142
  --> https://bugs.freedesktop.org/attachment.cgi?id=132142&action=edit
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|

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--- Comment #1 from dhruv.a.thakkar at leidos.com ---
Created attachment 132143
  --> https://bugs.freedesktop.org/attachment.cgi?id=132143&action=edit
/var/log/messages

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--- Comment #2 from dhruv.a.thakkar at leidos.com ---
Created attachment 132144
  --> https://bugs.freedesktop.org/attachment.cgi?id=132144&action=edit
xorg.conf for nouveau driver

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--- Comment #3 from Ilia Mirkin <imirkin at alum.mit.edu> ---
You appear to be using a 3.10 kernel. This was released in June 2013. Nouveau
has been rewritten ~3 times by now. Can you try more recent software?

Better DP link training logic is one of the things that has had a lot of
revisions to it.

Separately, you appear to want to use the card in Zaphod mode, but you
haven't
explicitly enabled it... no clue what happens when you do it that way.

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--- Comment #4 from dhruv.a.thakkar at leidos.com ---
Thanks for your response Ilia. 

I'm slightly confused by your comment. Currently, we are using Redhat 7.3
with
kernal version 3.10.0-514, which is the latest version available as shown here:
https://access.redhat.com/articles/3078

Nouveau's website indicates that the latest linux kernal available is
4.11.6.

I'm confused by this discrepancy, but I believe I'm misunderstanding
something.
Could you clarify a bit more?

Dhruv

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--- Comment #5 from Ilia Mirkin <imirkin at alum.mit.edu> ---
(In reply to dhruv.a.thakkar from comment #4)
> I'm slightly confused by your comment. Currently, we are using Redhat
7.3
> with kernal version 3.10.0-514, which is the latest version available as
> shown here: https://access.redhat.com/articles/3078
This isn't the RH support forum. This is upstream. http://www.kernel.org/
has
the relevant info of what the current kernel releases are.

Kernel 3.10 was released in 2013. Then someone at RH has been cherry-picking
"important" fixes for the past 4 years. The idea of such stable
branches is "if
it worked before, it'll keep working". However for you, it didn't
work
"before".

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Martin Peres <martin.peres at free.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |MOVED
             Status|NEW                         |RESOLVED

--- Comment #6 from Martin Peres <martin.peres at free.fr> ---
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been
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You can subscribe and participate further through the new bug through this link
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https://gitlab.freedesktop.org/xorg/driver/xf86-video-nouveau/issues/356.

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