I just installed Ubuntu 13.04 on my MacBook Pro 13" Retina. Everything works fine except that Ubuntu does not detect my external screen, which is plugged through a DVI to VGA adapter.
On System Settings - Displays, only the laptop screen appears - no sign of the external screen whatsoever even after clicking on Detect Displays. Note that the external screen is always plugged in, including during the boot process.
This MacBook comes with an Intel graphics card, as confirmed by a
lspci | grep VGA:
VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
Any idea of how I could fix this??
EDIT: additional info
sudo lshw -c video gives:
description: VGA compatible controller product: 3rd Gen Core processor Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@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:47 memory:a0000000-a03fffff memory:90000000-9fffffff ioport:2000(size=64)