From 3906e8089af3225a0a22c12cc3cf10be4630976e Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Tue, 21 Mar 2017 17:43:08 -0500 Subject: [PATCH] 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 Acked-by: William Breathitt Gray Signed-off-by: Linus Walleij --- drivers/gpio/gpio-104-idio-16.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c index 7053cf7..5281e1c 100644 --- a/drivers/gpio/gpio-104-idio-16.c +++ b/drivers/gpio/gpio-104-idio-16.c @@ -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) { -- 2.7.4