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PM / wakeirq: Fix unbalanced IRQ enable for wakeirq
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If a device is runtime PM suspended when we enter suspend and has
a dedicated wake IRQ, we can get the following warning:

WARNING: CPU: 0 PID: 108 at kernel/irq/manage.c:526 enable_irq+0x40/0x94
[  102.087860] Unbalanced enable for IRQ 147
...
(enable_irq) from [<c06117a8>] (dev_pm_arm_wake_irq+0x4c/0x60)
(dev_pm_arm_wake_irq) from [<c0618360>]
 (device_wakeup_arm_wake_irqs+0x58/0x9c)
(device_wakeup_arm_wake_irqs) from [<c0615948>]
(dpm_suspend_noirq+0x10/0x48)
(dpm_suspend_noirq) from [<c01ac7ac>]
(suspend_devices_and_enter+0x30c/0xf14)
(suspend_devices_and_enter) from [<c01adf20>]
(enter_state+0xad4/0xbd8)
(enter_state) from [<c01ad3ec>] (pm_suspend+0x38/0x98)
(pm_suspend) from [<c01ab3e8>] (state_store+0x68/0xc8)

This is because the dedicated wake IRQ for the device may have been
already enabled earlier by dev_pm_enable_wake_irq_check().  Fix the
issue by checking for runtime PM suspended status.

This issue can be easily reproduced by setting serial console log level
to zero, letting the serial console idle, and suspend the system from
an ssh terminal.  On resume, dmesg will have the warning above.

The reason why I have not run into this issue earlier has been that I
typically run my PM test cases from on a serial console instead over ssh.

Fixes: c843455 (PM / wakeirq: Enable dedicated wakeirq for suspend)
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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tmlind authored and rafaeljw committed Feb 12, 2018
1 parent 7928b2c commit 6972805
Showing 1 changed file with 4 additions and 2 deletions.
6 changes: 4 additions & 2 deletions drivers/base/power/wakeirq.c
Original file line number Diff line number Diff line change
Expand Up @@ -321,7 +321,8 @@ void dev_pm_arm_wake_irq(struct wake_irq *wirq)
return;

if (device_may_wakeup(wirq->dev)) {
if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)
if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
!pm_runtime_status_suspended(wirq->dev))
enable_irq(wirq->irq);

enable_irq_wake(wirq->irq);
Expand All @@ -343,7 +344,8 @@ void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
if (device_may_wakeup(wirq->dev)) {
disable_irq_wake(wirq->irq);

if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)
if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
!pm_runtime_status_suspended(wirq->dev))
disable_irq_nosync(wirq->irq);
}
}

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