From 0bf0ee8ef9a6c120f7f320b9fb5fe1270965d828 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Fri, 10 Feb 2017 14:25:01 -0800 Subject: [PATCH] PM / wakeirq: Fix spurious wake-up events for dedicated wakeirqs Dedicated wakeirq is a one time event to wake-up the system from low-power state and then call pm_runtime_resume() on the device wired with the dedicated wakeirq. Sometimes dedicated wakeirqs can get deferred if they trigger after we call disable_irq_nosync() in dev_pm_disable_wake_irq(). This can happen if pm_runtime_get() is called around the same time a wakeirq fires. If an interrupt fires after disable_irq_nosync(), by default it will get tagged with IRQS_PENDING and will run later on when the interrupt is enabled again. Deferred wakeirqs usually just produce pointless wake-up events. But they can also cause suspend to fail if the deferred wakeirq fires during dpm_suspend_noirq() for example. So we really don't want to see the deferred wakeirqs triggering after the device has resumed. Let's fix the issue by setting IRQ_DISABLE_UNLAZY flag for the dedicated wakeirqs. The other option would be to implement irq_disable() in the dedicated wakeirq controller, but that's not a generic solution. For reference below is what happens with a IRQ_TYPE_EDGE_BOTH IRQ type wakeirq: - resume by dedicated IRQ (EDGE_FALLING) - suspend_enter() .... - arch_suspend_enable_irqs() |- dedicated IRQ armed and fired |- irq_pm_check_wakeup() |- disarm, disable IRQ and mark as IRQS_PENDING .... - dpm_resume_noirq() |- resume_device_irqs() |- __enable_irq() |- check_irq_resend() |- handle_threaded_wake_irq() |- dedicated IRQ processed |- device_wakeup_disarm_wake_irqs() |- disable_irq_wake() .... !-> dedicated IRQ (EDGE_RISING) -| handle_edge_irq() |- IRQ disabled: mask_ack_irq and mark as IRQS_PENDING .... - subsequent suspend .... |- dpm_suspend_noirq() |- device_wakeup_arm_wake_irqs() |- __enable_irq() |- check_irq_resend() (a) |- handle_threaded_wake_irq() |- pm_wakeup_event() --> abort suspend .... |- suspend_device_irqs() |- suspend_device_irq() |- dedicated IRQ armed .... (b) |- resend_irqs |- irq_pm_check_wakeup() |- IRQ armed -> abort suspend because of pending IRQ System suspend can be aborted at points (a)-not armed or (b)-armed. Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling) Signed-off-by: Grygorii Strashko [ tony@atomide.com: added a comment, updated the description ] Tested-by: Tony Lindgren Signed-off-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki --- drivers/base/power/wakeirq.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c index 1b9fc7202933..06f103ce9d82 100644 --- a/drivers/base/power/wakeirq.c +++ b/drivers/base/power/wakeirq.c @@ -183,6 +183,9 @@ int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) wirq->irq = irq; irq_set_status_flags(irq, IRQ_NOAUTOEN); + /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */ + irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY); + /* * Consumer device may need to power up and restore state * so we use a threaded irq. -- 2.30.2