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gpio: 104-idio-16: make use of raw_spinlock variants 

The 104-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: Julia Cartwright <julia@ni.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Julia Cartwright 2017-03-21 17:43:08 -05:00 committed by Linus Walleij
parent 0e3cb6ee38
commit 3906e8089a
1 changed files with 12 additions and 12 deletions
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24
drivers/gpio/gpio-104-idio-16.c
View File

@ -50,7 +50,7 @@ MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers");
*/
struct idio_16_gpio {
struct gpio_chip chip;
spinlock_t lock;
raw_spinlock_t lock;
unsigned long irq_mask;
unsigned base;
unsigned out_state;
@ -99,7 +99,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
if (offset > 15)
return;
spin_lock_irqsave(&idio16gpio->lock, flags);
raw_spin_lock_irqsave(&idio16gpio->lock, flags);
if (value)
idio16gpio->out_state |= mask;
@ -111,7 +111,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
else
outb(idio16gpio->out_state, idio16gpio->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,
@ -120,7 +120,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
unsigned long flags;
spin_lock_irqsave(&idio16gpio->lock, flags);
raw_spin_lock_irqsave(&idio16gpio->lock, flags);
idio16gpio->out_state &= ~*mask;
idio16gpio->out_state |= *mask & *bits;
@ -130,7 +130,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
if ((*mask >> 8) & 0xFF)
outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
spin_unlock_irqrestore(&idio16gpio->lock, flags);
raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
static void idio_16_irq_ack(struct irq_data *data)
@ -147,11 +147,11 @@ 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);
outb(0, idio16gpio->base + 2);
spin_unlock_irqrestore(&idio16gpio->lock, flags);
raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
}
@ -166,11 +166,11 @@ 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);
inb(idio16gpio->base + 2);
spin_unlock_irqrestore(&idio16gpio->lock, flags);
raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
}
@ -201,11 +201,11 @@ 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);
outb(0, idio16gpio->base + 1);
spin_unlock(&idio16gpio->lock);
raw_spin_unlock(&idio16gpio->lock);
return IRQ_HANDLED;
}
@ -249,7 +249,7 @@ static int idio_16_probe(struct device *dev, unsigned int id)
idio16gpio->base = base[id];
idio16gpio->out_state = 0xFFFF;
spin_lock_init(&idio16gpio->lock);
raw_spin_lock_init(&idio16gpio->lock);
err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
if (err) {