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Commit fcce9f14 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Linus Walleij
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gpio: merrifield: Protect irq_ack() and gpio_set() by lock 



There is a potential race when two threads do the writes to the same register
in parallel.

Prevent out of order in such case by protecting I/O access by spin lock.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent ccf6fd6d

drivers/gpio/gpio-merrifield.c

+11 −0
Original line number Diff line number Diff line
@@ -105,7 +105,11 @@ static int mrfld_gpio_get(struct gpio_chip *chip, unsigned int offset) 
static void mrfld_gpio_set(struct gpio_chip *chip, unsigned int offset,

			   int value)

{

	struct mrfld_gpio *priv = gpiochip_get_data(chip);

	void __iomem *gpsr, *gpcr;

	unsigned long flags;



	raw_spin_lock_irqsave(&priv->lock, flags);



	if (value) {

		gpsr = gpio_reg(chip, offset, GPSR);
@@ -114,6 +118,8 @@ static void mrfld_gpio_set(struct gpio_chip *chip, unsigned int offset, 
		gpcr = gpio_reg(chip, offset, GPCR);

		writel(BIT(offset % 32), gpcr);

	}



	raw_spin_unlock_irqrestore(&priv->lock, flags);

}



static int mrfld_gpio_direction_input(struct gpio_chip *chip,
@@ -160,8 +166,13 @@ static void mrfld_irq_ack(struct irq_data *d) 
	struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);

	u32 gpio = irqd_to_hwirq(d);

	void __iomem *gisr = gpio_reg(&priv->chip, gpio, GISR);

	unsigned long flags;



	raw_spin_lock_irqsave(&priv->lock, flags);



	writel(BIT(gpio % 32), gisr);



	raw_spin_unlock_irqrestore(&priv->lock, flags);

}



static void mrfld_irq_unmask_mask(struct irq_data *d, bool unmask)