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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: Julia Cartwright <julia@ni.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Julia Cartwright 2017-03-09 10:21:55 -06:00 committed by Linus Walleij
parent a080ce53ee
commit f9c56536d5
1 changed files with 12 additions and 12 deletions
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24
drivers/gpio/gpio-etraxfs.c
View File

@ -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;