From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752898AbaHCNYP (ORCPT ); Sun, 3 Aug 2014 09:24:15 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:62170 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752486AbaHCNYN (ORCPT ); Sun, 3 Aug 2014 09:24:13 -0400 From: "Rafael J. Wysocki" To: Thomas Gleixner Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Linux PM list , Dmitry Torokhov Subject: Re: [PATCH 1/3] irq / PM: New driver interface for wakeup interruptsn Date: Sun, 03 Aug 2014 15:42:49 +0200 Message-ID: <9709483.qvfTdXg8SV@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1466301.X6ofroi0AB@vostro.rjw.lan> References: <20140724212620.GO3935@laptop> <3855585.ek3PTQLkmN@vostro.rjw.lan> <1466301.X6ofroi0AB@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Saturday, August 02, 2014 03:31:01 AM Rafael J. Wysocki wrote: > On Friday, August 01, 2014 04:29:40 PM Rafael J. Wysocki wrote: > > On Friday, August 01, 2014 03:43:21 PM Thomas Gleixner wrote: > > > On Fri, 1 Aug 2014, Rafael J. Wysocki wrote: > > > > OK, I guess "IRQ_HANDLED from a wakeup interrupt" may be interpreted as > > > > IRQ_HANDLED_PMWAKE. On the other hand, if that's going to be handled in > > > > handle_irq_event_percpu(), then using a special return code would save us > > > > a brach for IRQ_HANDLED interrupts. We could convert it to IRQ_HANDLED > > > > immediately then. > > > > > > We can handle it at the end of the function by calling > > > note_interrupt() unconditionally do the following there: > > > > > > if (suspended) { > > > if (ret == IRQ_NONE) { > > > if (shared) > > > yell_and_abort_or_resume(); > > > } else { > > > abort_or_resume(); > > > } > > > } > > > if (noirqdebug) > > > return; > > > > I see. > > > > > > OK, I'll take a stab at the IRQF_SHARED thing if you don't mind. > > > > > > Definitely not :) > > > > > > > Here's my current understanding of what can be done for IRQF_NO_SUSPEND. > > > > > > > > In suspend_device_irqs(): > > > > > > > > (1) If all actions in the list have the same setting (eg. IRQF_NO_SUSPEND unset), > > > > keep the current behavior. > > > > (2) If the actions have different settings: > > > > - Actions with IRQF_NO_SUSPEND set are not modified. > > > > - Actions with IRQF_NO_SUSPEND unset are switched over to a stub handler. > > > > - IRQS_SUSPEND_MODE (new flag) is set for the IRQ. > > > > > > Can we please do that in setup_irq() and let the shared ones always > > > run through the stub? That keeps suspend/resume_device_irqs() simple. > > > > OK > > I've tried to do that, but encountered a problem. The stub handler is called > with irq, dev_id as arguments and for the "interrupts are not suspended" case > (common) it has to use irq to find the irq_desc and then it has to use dev_id > to find the irqaction to call the original handler from there. That seemed to > be a bit too much of a penalty to me. Especially for people who never suspend > their machines. :-) > > For this reason, I went for changing handlers in suspend_device_irqs() and > back in resume_device_irqs(). That's not terribly complicated (the restoration > in particular is pretty simple) and it should be easily reusable for the wakeup > interrupts case. resume_device_irqs() wouldn't need any more changes for that, > for example. It minimally affects systems that don't suspend too. > > I also ended up adding a new interrupt handler return code (IRQ_SUSPENDED). > I could add a new irq_desc flag instead, but then the new code in suspend_device_irqs() > and the new check in note_interrupt() would need to be slightly more complicated. Actually, if we have a global irqs_suspended state variable, it will be much simpler to handle wakeup interrupts going forward, because in that case we'll be able to keep their original interrupt handlers and IRQ_HANDLED from them will be interpreted as a wakeup event automatically. Updated prototype follows. Rafael --- drivers/base/power/main.c | 1 + drivers/base/power/wakeup.c | 20 ++++++++++++++++++++ include/linux/interrupt.h | 2 ++ include/linux/suspend.h | 3 +++ kernel/irq/handle.c | 3 +-- kernel/irq/internals.h | 2 ++ kernel/irq/manage.c | 35 ++++++++++++++++++++++++++++++++++- kernel/irq/pm.c | 10 ++++++---- kernel/irq/spurious.c | 24 ++++++++++++++++++++++++ 9 files changed, 93 insertions(+), 7 deletions(-) Index: linux-pm/kernel/irq/manage.c =================================================================== --- linux-pm.orig/kernel/irq/manage.c +++ linux-pm/kernel/irq/manage.c @@ -382,11 +382,36 @@ setup_affinity(unsigned int irq, struct } #endif +/* + * Dummy handler for shared interrupts to use during system suspend. + */ +static irqreturn_t irq_pm_dummy_handler(int irq, void *dev_id) +{ + return IRQ_NONE; +} + void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend) { if (suspend) { - if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND)) + struct irqaction *action; + + if (!desc->action) return; + + for (action = desc->action; action; action = action->next) { + if (action->flags & IRQF_NO_SUSPEND) + break; + } + if (action) { + for (action = desc->action; action; action = action->next) { + if (!(action->flags & IRQF_NO_SUSPEND)) { + action->saved_handler = action->handler; + action->handler = irq_pm_dummy_handler; + } + } + return; + } + desc->istate |= IRQS_SUSPENDED; } @@ -445,6 +470,14 @@ EXPORT_SYMBOL(disable_irq); void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) { if (resume) { + struct irqaction *action; + + for (action = desc->action; action; action = action->next) { + if (action->handler == irq_pm_dummy_handler) { + action->handler = action->saved_handler; + action->saved_handler = NULL; + } + } if (!(desc->istate & IRQS_SUSPENDED)) { if (!desc->action) return; Index: linux-pm/include/linux/interrupt.h =================================================================== --- linux-pm.orig/include/linux/interrupt.h +++ linux-pm/include/linux/interrupt.h @@ -90,6 +90,7 @@ typedef irqreturn_t (*irq_handler_t)(int /** * struct irqaction - per interrupt action descriptor * @handler: interrupt handler function + * @saved_handler: saved pointer to interrupt handler function * @name: name of the device * @dev_id: cookie to identify the device * @percpu_dev_id: cookie to identify the device @@ -104,6 +105,7 @@ typedef irqreturn_t (*irq_handler_t)(int */ struct irqaction { irq_handler_t handler; + irq_handler_t saved_handler; void *dev_id; void __percpu *percpu_dev_id; struct irqaction *next; Index: linux-pm/kernel/irq/handle.c =================================================================== --- linux-pm.orig/kernel/irq/handle.c +++ linux-pm/kernel/irq/handle.c @@ -175,8 +175,7 @@ handle_irq_event_percpu(struct irq_desc add_interrupt_randomness(irq, flags); - if (!noirqdebug) - note_interrupt(irq, desc, retval); + note_interrupt(irq, desc, retval); return retval; } Index: linux-pm/kernel/irq/spurious.c =================================================================== --- linux-pm.orig/kernel/irq/spurious.c +++ linux-pm/kernel/irq/spurious.c @@ -13,10 +13,22 @@ #include #include #include +#include #include "internals.h" static int irqfixup __read_mostly; +static bool irqs_suspended __read_mostly; + +void set_irqs_suspended(bool on) +{ + struct irq_desc *desc; + int irq; + + irqs_suspended = on; + for_each_irq_desc(irq, desc) + synchronize_irq(irq); +} #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) static void poll_spurious_irqs(unsigned long dummy); @@ -275,6 +287,18 @@ try_misrouted_irq(unsigned int irq, stru void note_interrupt(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) { + if (unlikely(irqs_suspended && action_ret == IRQ_NONE)) { + pr_err_ratelimited("IRQ %d: Unhandled while suspended\n", irq); + desc->istate |= IRQS_SUSPENDED; + desc->depth++; + irq_disable(desc); + pm_system_wakeup(); + return; + } + + if (noirqdebug) + return; + if (desc->istate & IRQS_POLL_INPROGRESS || irq_settings_is_polled(desc)) return; Index: linux-pm/include/linux/suspend.h =================================================================== --- linux-pm.orig/include/linux/suspend.h +++ linux-pm/include/linux/suspend.h @@ -371,6 +371,8 @@ extern int unregister_pm_notifier(struct extern bool events_check_enabled; extern bool pm_wakeup_pending(void); +extern void pm_system_wakeup(void); +extern void pm_wakeup_clear(void); extern bool pm_get_wakeup_count(unsigned int *count, bool block); extern bool pm_save_wakeup_count(unsigned int count); extern void pm_wakep_autosleep_enabled(bool set); @@ -418,6 +420,7 @@ static inline int unregister_pm_notifier #define pm_notifier(fn, pri) do { (void)(fn); } while (0) static inline bool pm_wakeup_pending(void) { return false; } +static inline void pm_system_wakeup(void) {} static inline void lock_system_sleep(void) {} static inline void unlock_system_sleep(void) {} Index: linux-pm/drivers/base/power/wakeup.c =================================================================== --- linux-pm.orig/drivers/base/power/wakeup.c +++ linux-pm/drivers/base/power/wakeup.c @@ -691,6 +691,8 @@ void pm_print_active_wakeup_sources(void } EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources); +static bool abort_suspend; + /** * pm_wakeup_pending - Check if power transition in progress should be aborted. * @@ -712,6 +714,7 @@ bool pm_wakeup_pending(void) ret = (cnt != saved_count || inpr > 0); events_check_enabled = !ret; } + ret = ret || abort_suspend; spin_unlock_irqrestore(&events_lock, flags); if (ret) { @@ -722,6 +725,23 @@ bool pm_wakeup_pending(void) return ret; } +void pm_system_wakeup(void) +{ + unsigned long flags; + + spin_lock_irqsave(&events_lock, flags); + abort_suspend = true; + spin_unlock_irqrestore(&events_lock, flags); + freeze_wake(); +} + +void pm_wakeup_clear(void) +{ + spin_lock_irq(&events_lock); + abort_suspend = false; + spin_unlock_irq(&events_lock); +} + /** * pm_get_wakeup_count - Read the number of registered wakeup events. * @count: Address to store the value at. Index: linux-pm/drivers/base/power/main.c =================================================================== --- linux-pm.orig/drivers/base/power/main.c +++ linux-pm/drivers/base/power/main.c @@ -1648,6 +1648,7 @@ int dpm_suspend_start(pm_message_t state { int error; + pm_wakeup_clear(); error = dpm_prepare(state); if (error) { suspend_stats.failed_prepare++; Index: linux-pm/kernel/irq/pm.c =================================================================== --- linux-pm.orig/kernel/irq/pm.c +++ linux-pm/kernel/irq/pm.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "internals.h" @@ -33,10 +34,7 @@ void suspend_device_irqs(void) __disable_irq(desc, irq, true); raw_spin_unlock_irqrestore(&desc->lock, flags); } - - for_each_irq_desc(irq, desc) - if (desc->istate & IRQS_SUSPENDED) - synchronize_irq(irq); + set_irqs_suspended(true); } EXPORT_SYMBOL_GPL(suspend_device_irqs); @@ -90,6 +88,7 @@ device_initcall(irq_pm_init_ops); */ void resume_device_irqs(void) { + set_irqs_suspended(false); resume_irqs(false); } EXPORT_SYMBOL_GPL(resume_device_irqs); @@ -102,6 +101,9 @@ int check_wakeup_irqs(void) struct irq_desc *desc; int irq; + if (pm_wakeup_pending()) + return -EBUSY; + for_each_irq_desc(irq, desc) { /* * Only interrupts which are marked as wakeup source Index: linux-pm/kernel/irq/internals.h =================================================================== --- linux-pm.orig/kernel/irq/internals.h +++ linux-pm/kernel/irq/internals.h @@ -194,3 +194,5 @@ static inline void kstat_incr_irqs_this_ __this_cpu_inc(*desc->kstat_irqs); __this_cpu_inc(kstat.irqs_sum); } + +extern void set_irqs_suspended(bool on);