Add some basic resume trace facilities

Considering that there isn't a lot of hw we can depend on during resume,
this is about as good as it gets.

This is x86-only for now, although the basic concept (and most of the
code) will certainly work on almost any platform.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/power/Kconfig

@@ -36,6 +36,15 @@ config PM_DEBUG
 	code. This is helpful when debugging and reporting various PM bugs, 
 	like suspend support.
 
+config PM_TRACE
+	bool "Suspend/resume event tracing"
+	depends on PM && PM_DEBUG && X86
+	default y
+	---help---
+	This enables some cheesy code to save the last PM event point in the
+	RTC across reboots, so that you can debug a machine that just hangs
+	during suspend (or more commonly, during resume).
+
 config SOFTWARE_SUSPEND
 	bool "Software Suspend"
 	depends on PM && SWAP && (X86 && (!SMP || SUSPEND_SMP)) || ((FRV || PPC32) && !SMP)