+What; /sys/power/pm_trace_dev_match
+Date: October 2010
+Contact: James Hogan <james@albanarts.com>
+Description:
+ The /sys/power/pm_trace_dev_match file contains the name of the
+ device associated with the last PM event point saved in the RTC
+ across reboots when pm_trace has been used. More precisely it
+ contains the list of current devices (including those
+ registered by loadable kernel modules since boot) which match
+ the device hash in the RTC at boot, with a newline after each
+ one.
+
+ The advantage of this file over the hash matches printed to the
+ kernel log (see /sys/power/pm_trace), is that it includes
+ devices created after boot by loadable kernel modules.
+
+ Due to the small hash size necessary to fit in the RTC, it is
+ possible that more than one device matches the hash, in which
+ case further investigation is required to determine which
+ device is causing the problem. Note that genuine RTC clock
+ values (such as when pm_trace has not been used), can still
+ match a device and output it's name here.
+