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[Brian Murray <brian@xxxxxxxxxx>]

** Package changed: ubuntu => xorg (Ubuntu)

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https://bugs.launchpad.net/bugs/1398840

Title:
  dual monitors do not work on Mac Pro black cylinder

Status in xorg package in Ubuntu:
  New

Bug description:
  How do I get dual monitors working on a Mac Pro cylinder? I have two
  thunderbolt connected displays (one on a minidisplay port to dvi
  connector, and the other on a mini displayport to vga connector). If I
  plug only one in, it works. If I plug both in at boot up, than one of
  them will work randomly, and the other will not work at all.

  xrandr -q only shows the working one:

  $ xrandr -q
  xrandr: Failed to get size of gamma for output default
  Screen 0: minimum 1600 x 1200, current 1600 x 1200, maximum 1600 x 1200
  default connected primary 1600x1200+0+0 0mm x 0mm
     1600x1200      77.0* 

  I am using the kernel parameter nomodeset or video does not work at
  all.

  I am trying on Ubuntu 14.04 with kernel 3.13.0.39.46.

  # lshw -C display; lsb_release -a; uname -a
    *-display UNCLAIMED
         description: VGA compatible controller
         product: Tahiti LE [Radeon HD 7870 XT]
         vendor: Advanced Micro Devices, Inc. [AMD/ATI]
         physical id: 0
         bus info: pci@0000:02:00.0
         version: 00
         width: 64 bits
         clock: 33MHz
         capabilities: pm pciexpress msi vga_controller bus_master cap_list
         configuration: latency=0
         resources: memory:80000000-8fffffff memory:a0700000-a073ffff ioport:3000(size=256) memory:a0740000-a075ffff
    *-display UNCLAIMED
         description: VGA compatible controller
         product: Tahiti LE [Radeon HD 7870 XT]
         vendor: Advanced Micro Devices, Inc. [AMD/ATI]
         physical id: 0
         bus info: pci@0000:06:00.0
         version: 00
         width: 64 bits
         clock: 33MHz
         capabilities: pm pciexpress msi vga_controller bus_master cap_list
         configuration: latency=0
         resources: memory:90000000-9fffffff memory:a0600000-a063ffff ioport:2000(size=256) memory:a0640000-a065ffff
  No LSB modules are available.
  Distributor ID: Ubuntu
  Description: Ubuntu 14.04.1 LTS
  Release: 14.04
  Codename: trusty
  Linux inl426935 3.13.0-39-generic #66-Ubuntu SMP Tue Oct 28 13:30:27 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

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