[Suspend2-devel] CONFIG_ACPI_DOCK and changing dock state across a suspend

[Andrew Baumann]

Hi,

As of 2.6.18, Linux is gaining support for hot docking and undocking of 
laptops. The relevant config options are CONFIG_ACPI_DOCK and 
CONFIG_HOTPLUG_PCI_ACPI (and in my case CONFIG_HOTPLUG_PCI_ACPI_IBM). I can 
now insert and remove my thinkpad from a docking station, and extra devices 
show up and disappear from the PCI bus cleanly.

All great, but what does this have to do with software suspend? If I suspend 
while docked and try to resume while undocked, or vice versa, it fails 
miserably. It would be really nice to get this working, although I guess it's 
probably a bit tricky (somehow the software suspend code and ACPI dock driver 
need to be aware of each other).

Has anyone thought about this, or run into the same problem? If there's 
interest in fixing it or looking into it further, I'm happy to gather 
debugging info, etc. Of course, there is an obvious workaround (always 
suspend/resume when undocked, but this isn't kind to your battery).

Regards,
Andrew