Detecting Mini Dock Plus Series 3 dock presence

[racc]

I am using T410s with a ThinkPad Mini Dock Plus Series 3 dock. I want computer to select display configuration automatically based on docked/undocked status after boot.

I found a script ( http://askubuntu.com/questions/137927/u ... ng-station ) but unfortunately /sys/devices/platform/dock.0/docked in my system is always 0. On the other hand, /sys/devices/platform/dock.1/docked is always 1. Is this normal with Series 3 dock, or a kernel(?) configuration problem?

To change display configuration during dock/undock event, I use ACPI events. According to my understanding ACPI events are not generated if dock status is not changed.

Is there a clean way to detect dock presence? Currently my best idea is something like:

Code: Select all

lsusb |grep -c "ThinkPad Mini Dock Plus"

Not horribly bad, but leaves a feeling there could be a better way.