From 5a68e7a748c03127e6e54c353017cd19bffd2016 Mon Sep 17 00:00:00 2001
From: Doug Anderson <dianders@chromium.org>
Date: Mon, 17 Jun 2013 09:50:43 -0700
Subject: pinctrl: exynos: ack level-triggered interrupts before unmasking

A level-triggered interrupt should be acked after the interrupt line
becomes inactive and before it is unmasked, or else another interrupt
will be immediately triggered.  Acking before or after calling the
handler is not enough.

Signed-off-by: Luigi Semenzato <semenzato@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/pinctrl-exynos.c b/drivers/pinctrl/pinctrl-exynos.c
index c0729a3..ef75321 100644
--- a/drivers/pinctrl/pinctrl-exynos.c
+++ b/drivers/pinctrl/pinctrl-exynos.c
@@ -84,6 +84,17 @@ static void exynos_gpio_irq_unmask(struct irq_data *irqd)
 	unsigned long mask;
 	unsigned long flags;
 
+	/*
+	 * Ack level interrupts right before unmask
+	 *
+	 * If we don't do this we'll get a double-interrupt.  Level triggered
+	 * interrupts must not fire an interrupt if the level is not
+	 * _currently_ active, even if it was active while the interrupt was
+	 * masked.
+	 */
+	if (irqd_get_trigger_type(irqd) & IRQ_TYPE_LEVEL_MASK)
+		exynos_gpio_irq_ack(irqd);
+
 	spin_lock_irqsave(&bank->slock, flags);
 
 	mask = readl(d->virt_base + reg_mask);
@@ -302,6 +313,17 @@ static void exynos_wkup_irq_unmask(struct irq_data *irqd)
 	unsigned long mask;
 	unsigned long flags;
 
+	/*
+	 * Ack level interrupts right before unmask
+	 *
+	 * If we don't do this we'll get a double-interrupt.  Level triggered
+	 * interrupts must not fire an interrupt if the level is not
+	 * _currently_ active, even if it was active while the interrupt was
+	 * masked.
+	 */
+	if (irqd_get_trigger_type(irqd) & IRQ_TYPE_LEVEL_MASK)
+		exynos_wkup_irq_ack(irqd);
+
 	spin_lock_irqsave(&b->slock, flags);
 
 	mask = readl(d->virt_base + reg_mask);
-- 
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