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| author | Len Brown <len.brown@intel.com> | 2011-04-01 15:19:23 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2011-05-29 03:39:15 -0400 |
| commit | 99c63221435963e0cee2402686ba99293c2ffa9e (patch) | |
| tree | 7c73900db0eafed36291257494c1e084de6ad034 | |
| parent | 3b70b2e5fcf6315eb833a1bcc2b810bdc75484ff (diff) | |
| download | linux-99c63221435963e0cee2402686ba99293c2ffa9e.tar.gz linux-99c63221435963e0cee2402686ba99293c2ffa9e.tar.bz2 linux-99c63221435963e0cee2402686ba99293c2ffa9e.zip | |
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>
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/apm_32.c | 2 |
2 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 5540615ac26c..fc505c1b4762 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -14,6 +14,16 @@ Who: Len Brown <len.brown@intel.com> --------------------------- +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 diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c index 0e4f24c2a746..4c4ac32cd126 100644 --- a/arch/x86/kernel/apm_32.c +++ b/arch/x86/kernel/apm_32.c @@ -359,6 +359,7 @@ struct apm_user { * idle percentage above which bios idle calls are done */ #ifdef CONFIG_APM_CPU_IDLE +#warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012 #define DEFAULT_IDLE_THRESHOLD 95 #else #define DEFAULT_IDLE_THRESHOLD 100 @@ -902,6 +903,7 @@ static void apm_cpu_idle(void) unsigned int jiffies_since_last_check = jiffies - last_jiffies; unsigned int bucket; + WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012"); recalc: if (jiffies_since_last_check > IDLE_CALC_LIMIT) { use_apm_idle = 0; |