On Tuesday, August 20, 2013 02:08:33 PM Mika Westerberg wrote:

On Tue, Aug 20, 2013 at 01:47:57AM +0200, Rafael J. Wysocki wrote:

quoted

From: Rafael J. Wysocki <redacted>

Bad things happen if ACPI hotplug events are handled during system
PM transitions, especially if devices are removed as a result.
To prevent those bad things from happening, acquire acpi_scan_lock
when a transition is started and release it when that transition
is complete or has been aborted.

This fixes resume lockup on my test-bed Acer Aspire S5 that happens
when Thunderbolt devices are disconnected from the machine while
suspended.

Signed-off-by: Rafael J. Wysocki <redacted>

I tested this on Intel DZ77RE-75K and after the patch is applied the
machine didn't hang anymore once resuming.

Feel free to add my tested-by.

I will, thanks!