[Bug 907381] Re: Display resolution keeps switching with external monitor connected

[Timo Aaltonen]

You have a hybrid gfx setup, have you disabled the ATI chip from bios
(if possible)?

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

** Changed in: xorg (Ubuntu)
       Status: New => Incomplete

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https://bugs.launchpad.net/bugs/907381

Title:
  Display resolution keeps switching with external monitor connected

Status in “xorg” package in Ubuntu:
  Incomplete

Bug description:
  A fresh install of Ubuntu 11.10 on a Dell Vostro 3550 with all updates
  (OSS only - no proprietary drivers).

  When connecting the laptop to an external monitor to extend my desktop the display settings are unstable. I choose to enable both the laptop panel, and the external monitor setting appropriate resolutions and apply settings. Sometimes the chosen settings do not "take". If they do apply, and I confirm that I want to keep the settings, at random intervals the display settings are auto-changed by the system. This may include:
  - Resetting to "mirrored" displays at 1024x768
  - Resetting to a single display on the laptop panel
  - Resetting to a single display on the external monitor
  - Some other weird combination. 

  E.g. When using my computer in a time range of 10 minutes i could get
  through 5 different dispositions and resolutions. It could be both
  display working fine, then only one but with wrong resolution, then
  the two again but with mirror, then just the second, and so on..

  Some debug information below - happy to collect more if it's helpful.

  
  $ sudo lspci | grep VGA
  00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
  01:00.0 VGA compatible controller: ATI Technologies Inc NI Whistler [AMD Radeon HD 6600M Series]

  
  $ sudo lshw -C video
  *-display 
  description: VGA compatible controller
  product: NI Whistler [AMD Radeon HD 6600M Series]
  vendor: ATI Technologies Inc
  physical id: 0
  bus info: pci at 0000:01:00.0
  version: 00
  width: 64 bits
  clock: 33MHz
  capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
  configuration: driver=radeon latency=0
  resources: irq:52 memory:e0000000-efffffff memory:f7b20000-f7b3ffff ioport:e000(size=256) memory:f7b00000-f7b1ffff
  *-display
  description: VGA compatible controller
  product: 2nd Generation Core Processor Family Integrated Graphics Controller
  vendor: Intel Corporation
  physical id: 2
  bus info: pci at 0000:00:02.0
  version: 09
  width: 64 bits
  clock: 33MHz
  capabilities: msi pm vga_controller bus_master cap_list rom
  configuration: driver=i915 latency=0
  resources: irq:50 memory:f6400000-f67fffff memory:d0000000-dfffffff ioport:f000(size=64)

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