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 c0729a380bf5125b33c92a9dfc594356a242007f..ef7532121556fc8b8896bafb1e35f0d8b8133729 100644 (file)
--- 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);