kernel.git/drivers/acpi/processor_idle.c, branch linux-2.6.27.y

clockevent: Prevent dead lock on clockevents_lock

2010-05-26T21:27:07Z

This is a merge of two mainline commits, intended for stable@kernel.org submission for 2.6.27 kernel. commit f833bab87fca5c3ce13778421b1365845843b976 and commit 918aae42aa9b611a3663b16ae849fdedc67c2292 Changelog of both: Currently clockevents_notify() is called with interrupts enabled at some places and interrupts disabled at some other places. This results in a deadlock in this scenario. cpu A holds clockevents_lock in clockevents_notify() with irqs enabled cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled cpu C doing set_mtrr() which will try to rendezvous of all the cpus. This will result in C and A come to the rendezvous point and waiting for B. B is stuck forever waiting for the spinlock and thus not reaching the rendezvous point. Fix the clockevents code so that clockevents_lock is taken with interrupts disabled and thus avoid the above deadlock. Also call lapic_timer_propagate_broadcast() on the destination cpu so that we avoid calling smp_call_function() in the clockevents notifier chain. This issue left us wondering if we need to change the MTRR rendezvous logic to use stop machine logic (instead of smp_call_function) or add a check in spinlock debug code to see if there are other spinlocks which gets taken under both interrupts enabled/disabled conditions. Signed-off-by: Suresh Siddha Cc: "Brown Len" Cc: stable@kernel.org LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com> Signed-off-by: Thomas Gleixner I got following warning on ia64 box: In function 'acpi_processor_power_verify': 642: warning: passing argument 2 of 'smp_call_function_single' from incompatible pointer type This smp_call_function_single() was introduced by a commit f833bab87fca5c3ce13778421b1365845843b976: The problem is that the lapic_timer_propagate_broadcast() has 2 versions: One is real code that modified in the above commit, and the other is NOP code that used when !ARCH_APICTIMER_STOPS_ON_C3: static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } So I got warning because of !ARCH_APICTIMER_STOPS_ON_C3. We really want to do nothing here on !ARCH_APICTIMER_STOPS_ON_C3, so modify lapic_timer_propagate_broadcast() of real version to use smp_call_function_single() in it. Signed-off-by: Hidetoshi Seto Acked-by: Suresh Siddha Signed-off-by: Len Brown Signed-off-by: Thomas Renninger Signed-off-by: Greg Kroah-Hartman

cpuidle: make AMC C1E work in processor_idle

2009-06-12T03:01:21Z

commit 87ad57bacb25c3f24c54f142ef445f68277705f0 upstream When AMD C1E is enabled, local APIC timer will stop even in C1. This patch uses broadcast ipi to replace local APIC timer in C1. http://bugzilla.kernel.org/show_bug.cgi?id=13233 [ impact: avoid boot hang in AMD CPU with C1E enabled ] Tested-by: Dmitry Lyzhyn Signed-off-by: Shaohua Li Signed-off-by: Len Brown Signed-off-by: Greg Kroah-Hartman

cpuidle: fix AMD C1E suspend hang

2009-06-12T03:01:21Z

commit 7d60e8ab0d5507229dfbdf456501cc378610fa01 upstream. When AMD C1E is enabled, local APIC timer will stop even in C1. To avoid suspend/resume hang, this patch removes C1 and replace it with a cpu_relax() in suspend/resume path. This hasn't any impact in runtime path. http://bugzilla.kernel.org/show_bug.cgi?id=13233 [ impact: avoid suspend/resume hang in AMD CPU with C1E enabled ] Tested-by: Dmitry Lyzhyn Signed-off-by: Shaohua Li Signed-off-by: Len Brown Signed-off-by: Greg Kroah-Hartman

cpuidle: update the last_state acpi cpuidle reflecting actual state entered

2009-02-06T22:00:40Z

commit addbad46ed0906cd584784423b9d0babc7476446 reflect the actual state entered in dev->last_state, when actaul state entered is different from intended one. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown Cc: Thomas Renninger Signed-off-by: Greg Kroah-Hartman

acpi: trivial cleanups

2008-08-15T00:29:06Z

Trivial cleanups for ACPI. Fix misspelling in printk(), fix mismerge, add file header. AK: removed file header Signed-off-by: Pavel Machek Signed-off-by: Andi Kleen

ACPI/CPUIDLE: prevent setting pm_idle to NULL

2008-07-28T15:31:58Z

pm_idle_save resp. pm_idle_old can be NULL when the restore code in acpi_processor_cst_has_changed() resp. cpuidle_uninstall_idle_handler() is called. This can set pm_idle unconditinally to NULL, which causes the kernel to panic when calling pm_idle in the x86 idle code. This was covered by an extra check for !pm_idle in the x86 idle code, which was removed during the x86 idle code refactoring. Instead of restoring the pm_idle check in the x86 code prevent the acpi/cpuidle code to set pm_idle to NULL. Reported by: Dhaval Giani http://lkml.org/lkml/2008/7/2/309 Based on a debug patch from Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Linus Torvalds

ftrace: disable tracing on acpi idle calls

2008-07-26T12:42:21Z

The acpi idle waits calls local_irq_save and then uses mwait to go into idle. The tracer gets reenabled at local_irq_save but does not detect that the idle allows for wake ups. This patch adds code to disable the tracing when acpi puts the CPU to idle. Signed-off-by: Steven Rostedt Cc: Peter Zijlstra Signed-off-by: Ingo Molnar

ACPI : Create "idle=nomwait" bootparam

2008-07-16T21:27:05Z

"idle=nomwait" disables the use of the MWAIT instruction from both C1 (C1_FFH) and deeper (C2C3_FFH) C-states. When MWAIT is unavailable, the BIOS and OS generally negotiate to use the HALT instruction for C1, and use IO accesses for deeper C-states. This option is useful for power and performance comparisons, and also to work around BIOS bugs where broken MWAIT support is advertised. http://bugzilla.kernel.org/show_bug.cgi?id=10807 http://bugzilla.kernel.org/show_bug.cgi?id=10914 Signed-off-by: Zhao Yakui Signed-off-by: Li Shaohua Signed-off-by: Len Brown Signed-off-by: Andi Kleen

ACPI: Create "idle=halt" bootparam

2008-07-16T21:27:05Z

"idle=halt" limits the idle loop to using the halt instruction. No MWAIT, no IO accesses, no C-states deeper than C1. If something is broken in the idle code, "idle=halt" is a less severe workaround than "idle=poll" which disables all power savings. Signed-off-by: Zhao Yakui Signed-off-by: Len Brown Signed-off-by: Andi Kleen

ACPI: change processors from array to per_cpu variable

2008-07-16T21:27:01Z

Change processors from an array sized by NR_CPUS to a per_cpu variable. Signed-off-by: Mike Travis Signed-off-by: Andrew Morton Signed-off-by: Len Brown Signed-off-by: Andi Kleen