linux-kernel - [PATCH 2/2] mfd: sec-core: Fix IRQ handling after resume if this is not a wakeup source

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Message-id: <1398175225-20396-1-git-send-email-k.kozlowski@samsung.com>
Date:	Tue, 22 Apr 2014 16:00:25 +0200
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Samuel Ortiz <sameo@...ux.intel.com>,
	Lee Jones <lee.jones@...aro.org>,
	Sangbeom Kim <sbkim73@...sung.com>,
	linux-kernel@...r.kernel.org
Cc:	Kyungmin Park <kyungmin.park@...sung.com>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>
Subject: [PATCH 2/2] mfd: sec-core: Fix IRQ handling after resume if this is
 not a wakeup source

During suspend the IRQ should be disabled even if this is not a wakeup
source. This is a proper way of fixing the IRQ handling issue during
resume (IRQ handler fails because I2C bus did not resume yet).

When device is suspended and sec-core interrupt is signaled the irq chip
will try to handle it regardless of wakeup source. Device could be woken
up by different IRQ but still the IRQ handler will try to read the
registers over I2C bus and fail because I2C bus won't be ready yet.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@...sung.com>
---
 drivers/mfd/sec-core.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
index 1cf27521fff4..d2fecb9b37d5 100644
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -424,19 +424,18 @@ static int sec_pmic_suspend(struct device *dev)
 	struct i2c_client *i2c = container_of(dev, struct i2c_client, dev);
 	struct sec_pmic_dev *sec_pmic = i2c_get_clientdata(i2c);
 
-	if (device_may_wakeup(dev)) {
+	if (device_may_wakeup(dev))
 		enable_irq_wake(sec_pmic->irq);
-		/*
-		 * PMIC IRQ must be disabled during suspend for RTC alarm
-		 * to work properly.
-		 * When device is woken up from suspend by RTC Alarm, an
-		 * interrupt occurs before resuming I2C bus controller.
-		 * The interrupt is handled by regmap_irq_thread which tries
-		 * to read RTC registers. This read fails (I2C is still
-		 * suspended) and RTC Alarm interrupt is disabled.
-		 */
-		disable_irq(sec_pmic->irq);
-	}
+	/*
+	 * PMIC IRQ must be disabled during suspend for RTC alarm
+	 * to work properly.
+	 * When device is woken up from suspend, an
+	 * interrupt occurs before resuming I2C bus controller.
+	 * The interrupt is handled by regmap_irq_thread which tries
+	 * to read RTC registers. This read fails (I2C is still
+	 * suspended) and RTC Alarm interrupt is disabled.
+	 */
+	disable_irq(sec_pmic->irq);
 
 	return 0;
 }
@@ -446,10 +445,9 @@ static int sec_pmic_resume(struct device *dev)
 	struct i2c_client *i2c = container_of(dev, struct i2c_client, dev);
 	struct sec_pmic_dev *sec_pmic = i2c_get_clientdata(i2c);
 
-	if (device_may_wakeup(dev)) {
+	if (device_may_wakeup(dev))
 		disable_irq_wake(sec_pmic->irq);
-		enable_irq(sec_pmic->irq);
-	}
+	enable_irq(sec_pmic->irq);
 
 	return 0;
 }
-- 
1.9.1

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