x86 idle APM: deprecate CONFIG_APM_CPU_IDLE
We don't want to export the pm_idle function pointer to modules.
Currently CONFIG_APM_CPU_IDLE w/ CONFIG_APM_MODULE forces us to.
CONFIG_APM_CPU_IDLE is of dubious value, it runs only on 32-bit
uniprocessor laptops that are over 10 years old. It calls into
the BIOS during idle, and is known to cause a number of machines
to fail.
Removing CONFIG_APM_CPU_IDLE and will allow us to stop exporting
pm_idle. Any systems that were calling into the APM BIOS
at run-time will simply use HLT instead.
cc: x86@kernel.org
cc: Jiri Kosina <jkosina@suse.cz>
cc: stable@kernel.org # .39.x
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 5540615..fc505c1 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -14,6 +14,16 @@
---------------------------
+What: CONFIG_APM_CPU_IDLE, and its ability to call APM BIOS in idle
+When: 2012
+Why: This optional sub-feature of APM is of dubious reliability,
+ and ancient APM laptops are likely better served by calling HLT.
+ Deleting CONFIG_APM_CPU_IDLE allows x86 to stop exporting
+ the pm_idle function pointer to modules.
+Who: Len Brown <len.brown@intel.com>
+
+----------------------------
+
What: PRISM54
When: 2.6.34