From 25ac77613aa8fca131599705e3d7da2a0eaa06a0 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Thu, 5 Jul 2012 15:23:25 +0200 Subject: ACPI: intel_idle : break dependency between modules When the system is booted with some cpus offline, the idle driver is not initialized. When a cpu is set online, the acpi code call the intel idle init function. Unfortunately this code introduce a dependency between intel_idle and acpi. This patch is intended to remove this dependency by using the notifier of intel_idle. This patch has the benefit of encapsulating the intel_idle driver and remove some exported functions. Signed-off-by: Daniel Lezcano Acked-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_driver.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 0734086..8648b29 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -427,18 +427,11 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, * Initialize missing things */ if (pr->flags.need_hotplug_init) { - struct cpuidle_driver *idle_driver = - cpuidle_get_driver(); - printk(KERN_INFO "Will online and init hotplugged " "CPU: %d\n", pr->id); WARN(acpi_processor_start(pr), "Failed to start CPU:" " %d\n", pr->id); pr->flags.need_hotplug_init = 0; - if (idle_driver && !strcmp(idle_driver->name, - "intel_idle")) { - intel_idle_cpu_init(pr->id); - } /* Normal CPU soft online event */ } else { acpi_processor_ppc_has_changed(pr, 0); -- cgit v1.1 From 8651f97bd951d0bb1c10fa24e3fa3455193f3548 Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Mon, 9 Jul 2012 10:12:56 +0200 Subject: PM / cpuidle: System resume hang fix with cpuidle On certain bios, resume hangs if cpus are allowed to enter idle states during suspend [1]. This was fixed in apci idle driver [2].But intel_idle driver does not have this fix. Thus instead of replicating the fix in both the idle drivers, or in more platform specific idle drivers if needed, the more general cpuidle infrastructure could handle this. A suspend callback in cpuidle_driver could handle this fix. But a cpuidle_driver provides only basic functionalities like platform idle state detection capability and mechanisms to support entry and exit into CPU idle states. All other cpuidle functions are found in the cpuidle generic infrastructure for good reason that all cpuidle drivers, irrepective of their platforms will support these functions. One option therefore would be to register a suspend callback in cpuidle which handles this fix. This could be called through a PM_SUSPEND_PREPARE notifier. But this is too generic a notfier for a driver to handle. Also, ideally the job of cpuidle is not to handle side effects of suspend. It should expose the interfaces which "handle cpuidle 'during' suspend" or any other operation, which the subsystems call during that respective operation. The fix demands that during suspend, no cpus should be allowed to enter deep C-states. The interface cpuidle_uninstall_idle_handler() in cpuidle ensures that. Not just that it also kicks all the cpus which are already in idle out of their idle states which was being done during cpu hotplug through a CPU_DYING_FROZEN callbacks. Now the question arises about when during suspend should cpuidle_uninstall_idle_handler() be called. Since we are dealing with drivers it seems best to call this function during dpm_suspend(). Delaying the call till dpm_suspend_noirq() does no harm, as long as it is before cpu_hotplug_begin() to avoid race conditions with cpu hotpulg operations. In dpm_suspend_noirq(), it would be wise to place this call before suspend_device_irqs() to avoid ugly interactions with the same. Ananlogously, during resume. References: [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/674075. [2] http://marc.info/?l=linux-pm&m=133958534231884&w=2 Reported-and-tested-by: Dave Hansen Signed-off-by: Preeti U Murthy Reviewed-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 30 +----------------------------- 1 file changed, 1 insertion(+), 29 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 47a8caa..d8366ee 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -221,10 +221,6 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr, #endif -/* - * Suspend / resume control - */ -static int acpi_idle_suspend; static u32 saved_bm_rld; static void acpi_idle_bm_rld_save(void) @@ -243,21 +239,13 @@ static void acpi_idle_bm_rld_restore(void) int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) { - if (acpi_idle_suspend == 1) - return 0; - acpi_idle_bm_rld_save(); - acpi_idle_suspend = 1; return 0; } int acpi_processor_resume(struct acpi_device * device) { - if (acpi_idle_suspend == 0) - return 0; - acpi_idle_bm_rld_restore(); - acpi_idle_suspend = 0; return 0; } @@ -763,11 +751,6 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, local_irq_disable(); - if (acpi_idle_suspend) { - local_irq_enable(); - cpu_relax(); - return -EBUSY; - } lapic_timer_state_broadcast(pr, cx, 1); kt1 = ktime_get_real(); @@ -838,11 +821,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, local_irq_disable(); - if (acpi_idle_suspend) { - local_irq_enable(); - cpu_relax(); - return -EBUSY; - } if (cx->entry_method != ACPI_CSTATE_FFH) { current_thread_info()->status &= ~TS_POLLING; @@ -928,8 +906,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, drv, drv->safe_state_index); } else { local_irq_disable(); - if (!acpi_idle_suspend) - acpi_safe_halt(); + acpi_safe_halt(); local_irq_enable(); return -EBUSY; } @@ -937,11 +914,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, local_irq_disable(); - if (acpi_idle_suspend) { - local_irq_enable(); - cpu_relax(); - return -EBUSY; - } if (cx->entry_method != ACPI_CSTATE_FFH) { current_thread_info()->status &= ~TS_POLLING; -- cgit v1.1 From 64d45f07b433090ee1329cf74989d973875028cb Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Tue, 17 Jul 2012 22:15:24 +0200 Subject: cpuidle / ACPI : remove latency_ticks from acpi_processor_cx structure Remove the latency_ticks field as it is not used. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index d8366ee..b0d2bbe 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -583,7 +583,6 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr, */ cx->valid = 1; - cx->latency_ticks = cx->latency; /* * On older chipsets, BM_RLD needs to be set * in order for Bus Master activity to wake the @@ -616,7 +615,6 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) if (!cx->address) break; cx->valid = 1; - cx->latency_ticks = cx->latency; /* Normalize latency */ break; case ACPI_STATE_C3: -- cgit v1.1 From 53b70951d9ef68420775b69e59ba720cc15c2643 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Tue, 17 Jul 2012 22:16:00 +0200 Subject: cpuidle / ACPI: remove usage from acpi_processor_cx structure Remove the usage field as it is not used. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index b0d2bbe..f355f1a 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -760,7 +760,6 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, dev->last_residency = (int)idle_time; local_irq_enable(); - cx->usage++; lapic_timer_state_broadcast(pr, cx, 0); return index; @@ -863,8 +862,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, if (cx->entry_method != ACPI_CSTATE_FFH) current_thread_info()->status |= TS_POLLING; - cx->usage++; - lapic_timer_state_broadcast(pr, cx, 0); cx->time += idle_time; return index; @@ -984,8 +981,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, if (cx->entry_method != ACPI_CSTATE_FFH) current_thread_info()->status |= TS_POLLING; - cx->usage++; - lapic_timer_state_broadcast(pr, cx, 0); cx->time += idle_time; return index; -- cgit v1.1 From aa713cc3b22ccd24dc55df4e0770490781fe6a76 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Tue, 17 Jul 2012 22:16:04 +0200 Subject: cpuilde / ACPI: remove time from acpi_processor_cx structure Remove the time field as it is not used. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index f355f1a..4cf9648 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -863,7 +863,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, current_thread_info()->status |= TS_POLLING; lapic_timer_state_broadcast(pr, cx, 0); - cx->time += idle_time; return index; } @@ -982,7 +981,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, current_thread_info()->status |= TS_POLLING; lapic_timer_state_broadcast(pr, cx, 0); - cx->time += idle_time; return index; } -- cgit v1.1