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[Launchpad Bug Tracker <915400@xxxxxxxxxxxxxxxxxx>]

Status changed to 'Confirmed' because the bug affects multiple users.

** Changed in: lightdm (Ubuntu)
       Status: New => Confirmed

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https://bugs.launchpad.net/bugs/915400

Title:
  Second display (VGA) distorted and flickering on cold boot

Status in X.org XServer - ATI gfx chipset driver:
  Confirmed
Status in “lightdm” package in Ubuntu:
  Confirmed

Bug description:
  Summary:
  Suspected bug: cold boot driver initialization failure of HIS Radeon HD 6570
  Silence H657H(O)1G on VGA port with multiple monitors connected 
  Symptoms showing: cold boot -> lightdm (vga distorted) -> unity (unusable)
  Workaround 1:  cold boot -> lightdm (vga distorted) -> standby -> lightdm
  (flawless) -> unity (flawless)
  Workaround 2: using only a single monitor (either DVI or VGA works fine)
  Workaround 3: activate and use internal Radeon HD 4250 with dual monitor setup

  In detail:
  On the system listed below with Radeon HD 6570 configured (internal Radeon 4250
  deactivated in BIOS), when cold booting with dual monitors, the second monitor
  connected to the VGA port shows a distorted flickering image when starting up
  lightdm. 
  The BIOS and the purple ubuntu boot screen seem undistorted.
  When logging in through lightdm, Unity doesn't show any symbols on its launcher
  bar and is mostly unresponsive and unusable.

  Strangely the monitor initialization succeeds and work flawlessly when instead
  of logging in in lightdm, I order lightdm to go to standby mode and then wake
  the system up again. So it clearly seems to be a software initialization
  problem.
  This is a quite simple workaround, but a really bad user experience for the
  intended first time linux user.

  Tried suggested fixes in other bugs:
  Booting the system with 'radeon.modeset=0' does not work since lightdm wouldn't
  even start up.
  'avivotool regset 0x458 0x00000000' or 'avivotool regset 0x45c 0x00000000'
  didn't do anything.

  Using the system with only a single monitor installed (either the LCD via DVI
  or the CRT via VGA) it doesn't show any sign of initialization problems.
  Flawless operation is possible (but not desirable in this case).

  Only solution left was switching to the internal Radeon HD 4250 (only BIOS and
  connection changed), which initialized the dual monitor setup flawlessly. 

  The logfiles I gathered by switching from (distorted) lightdm to
  console.

  found possibly similar bugs on different hardware:
  https://bugs.freedesktop.org/show_bug.cgi?id=25741
  https://bugs.freedesktop.org/show_bug.cgi?id=27278

  Software:
  Ubuntu 11.10 amd64
  default software configuration: r600g, lightdm, Unity
  Dual View configuration:
  extended desktop, DVI on top, VGA below

  Core Hardware:
  AMD FX-6100 + Scythe Big Shuriken 2
  ASUS M5A88-M EVO (internal AMD Radeon 4250 deactivated) (BIOS 903)
  HIS Radeon HD 6570 Silence H657H1G (sticker on PCB says H657HO1G)
  Kingston ECC 8GB KVR1333D3E9SK2/8G

  Monitors:
  1: DVI, Dell 2209 WA @ 1680x1050
  2: VGA, Hyundai ImageQuest P910+ @ 1152x864 (alternatively tested with an old
  Iiyama Vision Master Pro CRT)

  Additional Hardware:
  Crucial m4 SSD 128GB CT128M4SSD2
  WD HDD WD20EARX
  LG GH24NS7
  EPoX BT-DG05A
  Be quiet! E8 400W
  Lian Li PC-V354B

  I have also filed this bug here:
  https://bugs.freedesktop.org/show_bug.cgi?id=44684
  but am not sure what the right location is for it.

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