From 99c63221435963e0cee2402686ba99293c2ffa9e Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 1 Apr 2011 15:19:23 -0400 Subject: [PATCH] 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 cc: stable@kernel.org # .39.x Signed-off-by: Len Brown --- Documentation/feature-removal-schedule.txt | 10 ++++++++++ arch/x86/kernel/apm_32.c | 2 ++ 2 files changed, 12 insertions(+) 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 --------------------------- +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 + +---------------------------- + 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; -- 2.20.1