[Bug 71660] New: displayport to dvi adapter preventing display detection

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=71660

          Priority: medium
            Bug ID: 71660
                CC: intel-gfx-bugs at lists.freedesktop.org
          Assignee: intel-gfx-bugs at lists.freedesktop.org
           Summary: displayport to dvi adapter preventing display
                    detection
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
          Severity: critical
    Classification: Unclassified
                OS: Linux (All)
          Reporter: kaneda18 at hotmail.com
          Hardware: x86 (IA32)
            Status: NEW
           Version: XOrg CVS
         Component: DRM/Intel
           Product: DRI

Created attachment 89290
  --> https://bugs.freedesktop.org/attachment.cgi?id=89290&action=edit
archive of log files

Hardware: Lenovo ThinkCentre M2600C
Chipset: Intel 2nd Gen Core Processor Family Integrated Graphics Controller
(rev 09) i915 driver
OS: Ubuntu 13.10
Kernel: 3.11
Intel Driver: 2.99.904
Monitors: Acer X223W 22" (VGA) and Asus VW224 22" (DVI with displayPort
adapter) 

Problem: If we use a DisplayPort to DVI/VGA adapter the monitor is not being
detected and remains in its sleep state. 

Reproduction Steps:

1. Plug in a VGA monitor into VGA port.
2. Plug in a DVI monitor via a DisplayPort to DVI adapter.
3. Boot Ubuntu 13.10 LiveUSB
4. Video will only output on the monitor connected via VGA - other monitor with
displayPort adapter slips into power saving mode after bios screens display
5. Run xrandr in the xterm to confirm only one display (VGA) is seen

The second monitor which is plugged in using the adapter remains in its sleep
state and is never seen or acknowledged by the OS. We see the exact same
behavior in our custom OS which is running the 3.8 kernel and an older version
of the Intel driver. 

If we use a regular DisplayPort monitor (no adapter) we have no problems with
getting video on the 2nd monitor. It is only when using these adapters (we've
tried about 5 different kinds) that we see this problem.  I'm pretty sure this
is happening in intel-drm as I can set drm.debug=14 in the boot command line
and get all sorts of information. 

Now here is where it gets interesting. If I roll back to Ubuntu 12.04 then the
monitor attached via the adapter now works however in xrandr it is listed as an
HDMI-1 monitor while it says DP1 is disconnected. Regardless we're able to get
video on both screens with an older kernel. I tracked it down to basically
anything running the 3.5 kernel or earlier seem to be working however the 3.6,
3.8 and 3.11 kernel have this issue.  The Ubuntu 12.04 distro is running the
Intel 2.17.0 module.  

I'm attaching both drm.debug=14 logs to provide some deeper insight. Included
is the dmesg logs from a working (good) kernel and a non-working (bad) kernel
build as well as the Xorg logs from the system.

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