[PATCH] prevent swsusp with PAE

PAE + swsusp results in hard-to-debug crash about 50% of time during
resume.  Cause is known, fix needs to be ported from x86-64 (but we can't
make it to 2.6.18, and I'd like this to be worked around in 2.6.18).

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/power/Kconfig

@@ -56,7 +56,7 @@ config PM_TRACE
 
 config SOFTWARE_SUSPEND
 	bool "Software Suspend"
-	depends on PM && SWAP && (X86 && (!SMP || SUSPEND_SMP)) || ((FRV || PPC32) && !SMP)
+	depends on PM && SWAP && ((X86 && (!SMP || SUSPEND_SMP) && !X86_PAE) || ((FRV || PPC32) && !SMP))
 	---help---
 	  Enable the possibility of suspending the machine.
 	  It doesn't need ACPI or APM.
@@ -78,6 +78,10 @@ config SOFTWARE_SUSPEND
 
 	  For more information take a look at <file:Documentation/power/swsusp.txt>.
 
+	  (For now, swsusp is incompatible with PAE aka HIGHMEM_64G on i386.
+	  we need identity mapping for resume to work, and that is trivial
+	  to get with 4MB pages, but less than trivial on PAE).
+
 config PM_STD_PARTITION
 	string "Default resume partition"
 	depends on SOFTWARE_SUSPEND