Bug 116361

This particular machine uses Intel i5-3320M processor. It does not have an external GPU. The machine supports two active outputs. In the bios there is an option to change output display during boot. I will describe the behaviour of booting verbosely to avoid confusion. Depending on the choice, and with two external monitors attached, the following happens:


 Laptop display as boot display, laptop lid open:
Boot loader shows up on the laptop display. External displays are off. After KMS loads, laptop display goes blank but the backlight stays on. External displays stay off.

 Laptop display as boot display, laptop lid closed:
Boot loader shows up on the first external display. Second external display is off. After KMS loads, first display goes blank but the backlight stays on. Second display stays off. Presumably, laptop display is off at all times.

 First external display as boot display, laptop lid open:
Boot loader shows up on the first external display. Other displays are off. After KMS loads, first display goes blank but the backlight stays on. Other displays stay off.

 First external monitor as boot display, laptop lid closed:
Boot loader shows up on the first external display. Second external display is off. After KMS loads, first display goes blank but the backlight stays on. Second display stays off. Presumably, laptop display is off at all times.


Setting the boot display to second external monitor behaves similarly as the last two cases, but with first and second monitor reversed.

Currently I'm using a dock to connect the two external monitors via DP and DVI - however, connecting them straight into the DP and VGA ports of the laptop has the same effect.

The machine is responsive after KMS, since I can log in and start X by memory, after which I have output as expected.

As a temporary fix I've added the kernel parameter "video=LVDS-1:d" which completely disables the internal laptop display during boot. This enables output on the external monitors after KMS loads. Downside of this is that I cannot detach external displays and continue working on the internal monitor without rebooting. Also, with only one external monitor attached, everything works as expected.