Laptop with Intel Graphics: external VGA monitor only gets signal on boot (no "hot plugging")
- by iveand
I am able to get an external VGA monitor (or projector) to work if I start my laptop with it connected. However, if I start the laptop with it disconnected there is no signal on the external. The Displays screen shows the external, and thinks that it is active, but there is no signal being sent to it. This has been a persistent problem since 10.04 (I am now on 12.04.... each upgrade hoping something is improved).
I should note that even when it works (starting with display connected), Displays still says the monitor is "unknown" (but it sends the signal). For the correct resolution to display, I have had to add a few xrandr lines for my monitor to my .xprofile file... otherwise resolution is limited to default 1024x768. So, resolution issues can be worked around, but the main issue is that the external doesn't get a signal without starting the machine with it connected.
I have tried:
adding i915.modeset=1 to grub (also i965.modeset=1 since someone posted that this helped even though lshw shows i915)
adding following ppa and doing a dist-upgrade: sudo add-apt-repository ppa:xorg-edgers/ppa
Here are the details:
Laptop: Toshiba Tecra M10
lspci listings for video:
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07)
sudo lshw -C video listing:
*-display:0
description: VGA compatible controller
product: Mobile 4 Series Chipset Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 07
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:46 memory:ff400000-ff7fffff memory:e0000000-efffffff ioport:cff8(size=8)
*-display:1 UNCLAIMED
description: Display controller
product: Mobile 4 Series Chipset Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2.1
bus info: pci@0000:00:02.1
version: 07
width: 64 bits
clock: 33MHz
capabilities: pm bus_master cap_list
configuration: latency=0
resources: memory:ffc00000-ffcfffff
"System Info" shows my graphics as the following
Mobile Intel® GM45 Express Chipset x86/MMX/SSE2
