Arch Linux

korpenkraxar

Member

Registered: 2006-04-02

Posts: 123

Thinkpad W500: no to resume if external monitor removed during suspend

Hi all!

I have been having some troubles lately with resuming from suspend on my Thinkpad W500. I usually have it connected to external monitors over Displayport both at home and at office (albeit different monitors and resolutions). When resuming, all status leds on the laptop indicate that the computer is back up, but neither the laptop LCD nor the external monitor light up again and after a few seconds I can hear the fan stop or spin down. I need to reset the laptop by long pressing the power button.

I can reproduce this resume failure with 100% "success" rate. It happens if the state of the external monitor connection has changed while the laptop was sleeping, for instance if the external monitor has been disconnected and is no longer attached when the laptop resumes. However, the problem only occurs if the laptop wakes up due to an "open lid event", which is most often the case when moving a sleeping laptop around. If I only put the laptop to sleep, disconnected the external monitor and wake it up by pressing the power button, having never closed the lid, it works just fine. That obviously does not work well if the laptop needs to be moved around much. Remembering to disconnect the external monitor before suspending the laptop and closing the lid works ok, although I am a stupid, slow-learning bastard who often forget doing it this way.

I think resume fails also when the laptop resumes to a different monitor (e.g. at the office) being connected than the one that was connected upon suspend (e.g. at home) on the same Displayport connection, but I need to check this again on Monday. I have not yet tried all this on  VGA cables.

Are there any suggestions out there on how to further look into the lid problem? I do not remember always having this issue, but it happens on both 2.6.35 and the new 2.6.36 kernels. I recently upgraded both X11 and Gnome to the current stable versions in Arch though.

EDIT: Here is an additional observation: If the laptop is suspended without an external monitor attached and one is connected while it suspended, it resumes ok, but then the mouse pointer is only visible on the laptop LCD when it resumes, although screens are mirrored.

Last edited by korpenkraxar (2010-10-24 20:14:55)