x86 idle floppy: deprecate disable_hlt()

Plan to remove floppy_disable_hlt in 2012, an ancient
workaround with comments that it should be removed.

This allows us to remove clutter and a run-time branch
from the idle code.

WARN_ONCE() on invocation until it is removed.

cc: x86@kernel.org
cc: stable@kernel.org # .39.x
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/feature-removal-schedule.txt

@@ -6,6 +6,14 @@ be removed from this file.
 
 ---------------------------
 
+What:	x86 floppy disable_hlt
+When:	2012
+Why:	ancient workaround of dubious utility clutters the
+	code used by everybody else.
+Who:	Len Brown <len.brown@intel.com>
+
+---------------------------
+
 What:	PRISM54
 When:	2.6.34
 

drivers/block/floppy.c

@@ -1038,6 +1038,7 @@ static void floppy_disable_hlt(void)
 {
 	unsigned long flags;
 
+	WARN_ONCE(1, "floppy_disable_hlt() scheduled for removal in 2012");
 	spin_lock_irqsave(&floppy_hlt_lock, flags);
 	if (!hlt_disabled) {
 		hlt_disabled = 1;