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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Tony Lindgren <tony@atomide.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.14 152/161] PM / wakeirq: Fix unbalanced IRQ
 enable for wakeirq
Thread-Topic: [PATCH AUTOSEL for 4.14 152/161] PM / wakeirq: Fix unbalanced
 IRQ enable for wakeirq
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Date:   Mon, 9 Apr 2018 00:21:57 +0000
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From: Tony Lindgren <tony@atomide.com>

[ Upstream commit 69728051f5bf15efaf6edfbcfe1b5a49a2437918 ]

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: c84345597558 (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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/base/power/wakeirq.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
index ae0429827f31..67c50738834b 100644
--- a/drivers/base/power/wakeirq.c
+++ b/drivers/base/power/wakeirq.c
@@ -323,7 +323,8 @@ void dev_pm_arm_wake_irq(struct wake_irq *wirq)
 		return;
=20
 	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);
=20
 		enable_irq_wake(wirq->irq);
@@ -345,7 +346,8 @@ void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
 	if (device_may_wakeup(wirq->dev)) {
 		disable_irq_wake(wirq->irq);
=20
-		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);
 	}
 }
--=20
2.15.1