Commit f9c56536 authored by Julia Cartwright's avatar Julia Cartwright Committed by Linus Walleij
Browse files

gpio: etraxfs: make use of raw_spinlock variants 



The etraxfs 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>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent a080ce53

drivers/gpio/gpio-etraxfs.c

+12 −12
Original line number Diff line number Diff line
@@ -54,7 +54,7 @@ 
struct etraxfs_gpio_info;



struct etraxfs_gpio_block {

	spinlock_t lock;

	raw_spinlock_t lock;

	u32 mask;

	u32 cfg;

	u32 pins;
@@ -233,10 +233,10 @@ static void etraxfs_gpio_irq_mask(struct irq_data *d) 
	struct etraxfs_gpio_block *block = chip->block;

	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);



	spin_lock(&block->lock);

	raw_spin_lock(&block->lock);

	block->mask &= ~BIT(grpirq);

	writel(block->mask, block->regs + block->info->rw_intr_mask);

	spin_unlock(&block->lock);

	raw_spin_unlock(&block->lock);

}



static void etraxfs_gpio_irq_unmask(struct irq_data *d)
@@ -246,10 +246,10 @@ static void etraxfs_gpio_irq_unmask(struct irq_data *d) 
	struct etraxfs_gpio_block *block = chip->block;

	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);



	spin_lock(&block->lock);

	raw_spin_lock(&block->lock);

	block->mask |= BIT(grpirq);

	writel(block->mask, block->regs + block->info->rw_intr_mask);

	spin_unlock(&block->lock);

	raw_spin_unlock(&block->lock);

}



static int etraxfs_gpio_irq_set_type(struct irq_data *d, u32 type)
@@ -280,11 +280,11 @@ static int etraxfs_gpio_irq_set_type(struct irq_data *d, u32 type) 
		return -EINVAL;

	}



	spin_lock(&block->lock);

	raw_spin_lock(&block->lock);

	block->cfg &= ~(0x7 << (grpirq * 3));

	block->cfg |= (cfg << (grpirq * 3));

	writel(block->cfg, block->regs + block->info->rw_intr_cfg);

	spin_unlock(&block->lock);

	raw_spin_unlock(&block->lock);



	return 0;

}
@@ -297,7 +297,7 @@ static int etraxfs_gpio_irq_request_resources(struct irq_data *d) 
	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);

	int ret = -EBUSY;



	spin_lock(&block->lock);

	raw_spin_lock(&block->lock);

	if (block->group[grpirq])

		goto out;
@@ -316,7 +316,7 @@ static int etraxfs_gpio_irq_request_resources(struct irq_data *d) 
	}



out:

	spin_unlock(&block->lock);

	raw_spin_unlock(&block->lock);

	return ret;

}
@@ -327,10 +327,10 @@ static void etraxfs_gpio_irq_release_resources(struct irq_data *d) 
	struct etraxfs_gpio_block *block = chip->block;

	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);



	spin_lock(&block->lock);

	raw_spin_lock(&block->lock);

	block->group[grpirq] = 0;

	gpiochip_unlock_as_irq(&chip->gc, d->hwirq);

	spin_unlock(&block->lock);

	raw_spin_unlock(&block->lock);

}



static struct irq_chip etraxfs_gpio_irq_chip = {
@@ -391,7 +391,7 @@ static int etraxfs_gpio_probe(struct platform_device *pdev) 
	if (!block)

		return -ENOMEM;



	spin_lock_init(&block->lock);

	raw_spin_lock_init(&block->lock);



	block->regs = regs;

	block->info = info;

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