[PATCH 2/3] pinctrl:Intel: clear interrupt status for every IRQ setup

[Qipeng Zha <qipeng.zha@xxxxxxxxx>]

There is one unexpected GPIO interrupt coming in below scenario.
1. GPIO X is going to be used as falling edge interrupt.
2. Before request_irq call, this GPIO X interrupt was masked.
3. But the IRQ mode may be set for some mode in default (by BIOS).
4. Toggle GPIO X from high to low.
5. The GPIO X interrupt status will be set even if it was masked.
6. Register the interrupt for GPIO X, the interrupt will be unmasked.
7. Even if no change on GPIO X afterwards, but one GPIO X interrupt
will be triggered because the interrupt status was set.

To avoid above issue, the interrupt status need clear before request_irq.

Signed-off-by: Qi Zheng <qi.zheng@xxxxxxxxx>
Signed-off-by: Qipeng Zha <qipeng.zha@xxxxxxxxx>
---
 drivers/pinctrl/intel/pinctrl-intel.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
index ded5378..d6fe659 100644
--- a/drivers/pinctrl/intel/pinctrl-intel.c
+++ b/drivers/pinctrl/intel/pinctrl-intel.c
@@ -773,6 +773,8 @@ static int intel_gpio_irq_type(struct irq_data *d, unsigned type)
 		return -EPERM;
 	}
 
+	intel_gpio_irq_ack(d);
+
 	spin_lock_irqsave(&pctrl->lock, flags);
 
 	value = readl(reg);
-- 
1.8.3.2

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