From a080ce53eea56407779eb7ccf0ff00af0734bcdf Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Thu, 9 Mar 2017 10:21:53 -0600 Subject: [PATCH] gpio: ath79: make use of raw_spinlock variants The ath79 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: Aban Bedel Signed-off-by: Linus Walleij --- drivers/gpio/gpio-ath79.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/gpio/gpio-ath79.c b/drivers/gpio/gpio-ath79.c index dc37dbe4b46d..f33d4a5fe671 100644 --- a/drivers/gpio/gpio-ath79.c +++ b/drivers/gpio/gpio-ath79.c @@ -32,7 +32,7 @@ struct ath79_gpio_ctrl { struct gpio_chip gc; void __iomem *base; - spinlock_t lock; + raw_spinlock_t lock; unsigned long both_edges; }; @@ -74,9 +74,9 @@ static void ath79_gpio_irq_unmask(struct irq_data *data) u32 mask = BIT(irqd_to_hwirq(data)); unsigned long flags; - spin_lock_irqsave(&ctrl->lock, flags); + raw_spin_lock_irqsave(&ctrl->lock, flags); ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask); - spin_unlock_irqrestore(&ctrl->lock, flags); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); } static void ath79_gpio_irq_mask(struct irq_data *data) @@ -85,9 +85,9 @@ static void ath79_gpio_irq_mask(struct irq_data *data) u32 mask = BIT(irqd_to_hwirq(data)); unsigned long flags; - spin_lock_irqsave(&ctrl->lock, flags); + raw_spin_lock_irqsave(&ctrl->lock, flags); ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0); - spin_unlock_irqrestore(&ctrl->lock, flags); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); } static void ath79_gpio_irq_enable(struct irq_data *data) @@ -96,10 +96,10 @@ static void ath79_gpio_irq_enable(struct irq_data *data) u32 mask = BIT(irqd_to_hwirq(data)); unsigned long flags; - spin_lock_irqsave(&ctrl->lock, flags); + raw_spin_lock_irqsave(&ctrl->lock, flags); ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask); ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask); - spin_unlock_irqrestore(&ctrl->lock, flags); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); } static void ath79_gpio_irq_disable(struct irq_data *data) @@ -108,10 +108,10 @@ static void ath79_gpio_irq_disable(struct irq_data *data) u32 mask = BIT(irqd_to_hwirq(data)); unsigned long flags; - spin_lock_irqsave(&ctrl->lock, flags); + raw_spin_lock_irqsave(&ctrl->lock, flags); ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0); ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0); - spin_unlock_irqrestore(&ctrl->lock, flags); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); } static int ath79_gpio_irq_set_type(struct irq_data *data, @@ -140,7 +140,7 @@ static int ath79_gpio_irq_set_type(struct irq_data *data, return -EINVAL; } - spin_lock_irqsave(&ctrl->lock, flags); + raw_spin_lock_irqsave(&ctrl->lock, flags); if (flow_type == IRQ_TYPE_EDGE_BOTH) { ctrl->both_edges |= mask; @@ -165,7 +165,7 @@ static int ath79_gpio_irq_set_type(struct irq_data *data, ath79_gpio_update_bits( ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask); - spin_unlock_irqrestore(&ctrl->lock, flags); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); return 0; } @@ -191,7 +191,7 @@ static void ath79_gpio_irq_handler(struct irq_desc *desc) chained_irq_enter(irqchip, desc); - spin_lock_irqsave(&ctrl->lock, flags); + raw_spin_lock_irqsave(&ctrl->lock, flags); pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING); @@ -203,7 +203,7 @@ static void ath79_gpio_irq_handler(struct irq_desc *desc) both_edges, ~state); } - spin_unlock_irqrestore(&ctrl->lock, flags); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); if (pending) { for_each_set_bit(irq, &pending, gc->ngpio) @@ -262,7 +262,7 @@ static int ath79_gpio_probe(struct platform_device *pdev) if (!ctrl->base) return -ENOMEM; - spin_lock_init(&ctrl->lock); + raw_spin_lock_init(&ctrl->lock); err = bgpio_init(&ctrl->gc, &pdev->dev, 4, ctrl->base + AR71XX_GPIO_REG_IN, ctrl->base + AR71XX_GPIO_REG_SET,