Commit ea38ce08 authored by Julia Cartwright's avatar Julia Cartwright Committed by Linus Walleij
Browse files

gpio: pci-idio-16: make use of raw_spinlock variants 



The pci-idio-16 gpio driver currently implements an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel.  Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.

A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.

Signed-off-by: default avatarJulia Cartwright <julia@ni.com>
Acked-by: default avatarWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 3906e808

drivers/gpio/gpio-pci-idio-16.c

+14 −14
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ struct idio_16_gpio_reg { 
 */

struct idio_16_gpio {

	struct gpio_chip chip;

	spinlock_t lock;

	raw_spinlock_t lock;

	struct idio_16_gpio_reg __iomem *reg;

	unsigned long irq_mask;

};
@@ -121,7 +121,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, 
	} else

		base = &idio16gpio->reg->out0_7;



	spin_lock_irqsave(&idio16gpio->lock, flags);

	raw_spin_lock_irqsave(&idio16gpio->lock, flags);



	if (value)

		out_state = ioread8(base) | mask;
@@ -130,7 +130,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, 


	iowrite8(out_state, base);



	spin_unlock_irqrestore(&idio16gpio->lock, flags);

	raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);

}



static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
@@ -140,7 +140,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip, 
	unsigned long flags;

	unsigned int out_state;



	spin_lock_irqsave(&idio16gpio->lock, flags);

	raw_spin_lock_irqsave(&idio16gpio->lock, flags);



	/* process output lines 0-7 */

	if (*mask & 0xFF) {
@@ -160,7 +160,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip, 
		iowrite8(out_state, &idio16gpio->reg->out8_15);

	}



	spin_unlock_irqrestore(&idio16gpio->lock, flags);

	raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);

}



static void idio_16_irq_ack(struct irq_data *data)
@@ -177,11 +177,11 @@ static void idio_16_irq_mask(struct irq_data *data) 
	idio16gpio->irq_mask &= ~mask;



	if (!idio16gpio->irq_mask) {

		spin_lock_irqsave(&idio16gpio->lock, flags);

		raw_spin_lock_irqsave(&idio16gpio->lock, flags);



		iowrite8(0, &idio16gpio->reg->irq_ctl);



		spin_unlock_irqrestore(&idio16gpio->lock, flags);

		raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);

	}

}
@@ -196,11 +196,11 @@ static void idio_16_irq_unmask(struct irq_data *data) 
	idio16gpio->irq_mask |= mask;



	if (!prev_irq_mask) {

		spin_lock_irqsave(&idio16gpio->lock, flags);

		raw_spin_lock_irqsave(&idio16gpio->lock, flags);



		ioread8(&idio16gpio->reg->irq_ctl);



		spin_unlock_irqrestore(&idio16gpio->lock, flags);

		raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);

	}

}
@@ -229,11 +229,11 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) 
	struct gpio_chip *const chip = &idio16gpio->chip;

	int gpio;



	spin_lock(&idio16gpio->lock);

	raw_spin_lock(&idio16gpio->lock);



	irq_status = ioread8(&idio16gpio->reg->irq_status);



	spin_unlock(&idio16gpio->lock);

	raw_spin_unlock(&idio16gpio->lock);



	/* Make sure our device generated IRQ */

	if (!(irq_status & 0x3) || !(irq_status & 0x4))
@@ -242,12 +242,12 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) 
	for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)

		generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));



	spin_lock(&idio16gpio->lock);

	raw_spin_lock(&idio16gpio->lock);



	/* Clear interrupt */

	iowrite8(0, &idio16gpio->reg->in0_7);



	spin_unlock(&idio16gpio->lock);

	raw_spin_unlock(&idio16gpio->lock);



	return IRQ_HANDLED;

}
@@ -302,7 +302,7 @@ static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	idio16gpio->chip.set = idio_16_gpio_set;

	idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;



	spin_lock_init(&idio16gpio->lock);

	raw_spin_lock_init(&idio16gpio->lock);



	err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);

	if (err) {

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