[Bug 77156] New: One screen black in Zaphod configuration (regression)

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=77156

          Priority: medium
            Bug ID: 77156
          Assignee: chris at chris-wilson.co.uk
           Summary: One screen black in Zaphod configuration (regression)
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
          Severity: normal
    Classification: Unclassified
                OS: All
          Reporter: nbowler at draconx.ca
          Hardware: Other
            Status: NEW
           Version: git
         Component: Driver/intel
           Product: xorg

Created attachment 97050
  --> https://bugs.freedesktop.org/attachment.cgi?id=97050&action=edit
Xorg log

After updating xf86-video-intel to latest my primary display in a zaphod
configuration shows black.  FWIW, the problematic display is connected via
HDMI; but the VGA display is still working.  The display is "gone" in that I
cannot move the mouse cursor off of the VGA display, although if I run xrandr
it is still there in spirit, but apparently configured to an 8x8 mode.

  % echo $DISPLAY
  :2.1
  % xrandr -display :2.0
  Screen 0: minimum 8 x 8, current 8 x 8, maximum 32767 x 32767
  HDMI1 connected (normal left inverted right x axis y axis)
     1920x1080      59.9 +   60.0     60.0     50.0     59.9  
     1920x1080i     60.1     50.0     60.0  
     1680x1050      59.9  
     1280x1024      75.0     60.0  
     1152x864       75.0  
     1280x720       60.0     50.0     59.9  
     1024x768       75.1     60.0  
     832x624        74.6  
     800x600        75.0     60.3     56.2  
     720x576        50.0  
     720x480        60.0     59.9  
     640x480        75.0     60.0     59.9  
     720x400        70.1  
  VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Bisection pinpoints the following as the problematic commit, and reverting
this commit corrects the issue.

  35b03b3fe6213eb3e08f05efe3428bd6bc5421d2 is the first bad commit
  commit 35b03b3fe6213eb3e08f05efe3428bd6bc5421d2
  Author: Chris Wilson <chris at chris-wilson.co.uk>
  Date:   Fri Mar 28 09:14:59 2014 +0000

      sna: Virtual CRTCs are last, so break loops early

      We know that all the virtual CRTCs are at the end of the CRTC array, so
      when we see the first one, we can stop the processing of real CRTCs.

      Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

  :040000 040000 b9e518145aae38b28e7bdd18c72f5d123901424f
2380f4e62562601f678258f4363402b3da9be615 M    src

server 1.15.0
libdrm 2.4.52
linux  3.12.5

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20140407/6d4841f9/attachment.html>