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authorJulia Cartwright2017-03-21 17:43:07 -0500
committerLinus Walleij2017-03-28 14:55:08 +0200
commite1e37d6c4a78bb6fb9b67115f497337cb38de503 (patch)
tree86ca3250c46d75dcede1cd179fa1120cd72a7029 /drivers/gpio
parentea38ce081d155534494bac5df2bb0d343fb1679b (diff)
gpio: 104-idi-48: make use of raw_spinlock variants
The 104-idi-48 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>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpio-104-idi-48.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index 568375a7ebc2..337c048168d8 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -51,7 +51,7 @@ MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
*/
struct idi_48_gpio {
struct gpio_chip chip;
- spinlock_t lock;
+ raw_spinlock_t lock;
spinlock_t ack_lock;
unsigned char irq_mask[6];
unsigned base;
@@ -112,11 +112,12 @@ static void idi_48_irq_mask(struct irq_data *data)
if (!idi48gpio->irq_mask[boundary]) {
idi48gpio->cos_enb &= ~BIT(boundary);
- spin_lock_irqsave(&idi48gpio->lock, flags);
+ raw_spin_lock_irqsave(&idi48gpio->lock, flags);
outb(idi48gpio->cos_enb, idi48gpio->base + 7);
- spin_unlock_irqrestore(&idi48gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idi48gpio->lock,
+ flags);
}
return;
@@ -145,11 +146,12 @@ static void idi_48_irq_unmask(struct irq_data *data)
if (!prev_irq_mask) {
idi48gpio->cos_enb |= BIT(boundary);
- spin_lock_irqsave(&idi48gpio->lock, flags);
+ raw_spin_lock_irqsave(&idi48gpio->lock, flags);
outb(idi48gpio->cos_enb, idi48gpio->base + 7);
- spin_unlock_irqrestore(&idi48gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idi48gpio->lock,
+ flags);
}
return;
@@ -186,11 +188,11 @@ static irqreturn_t idi_48_irq_handler(int irq, void *dev_id)
spin_lock(&idi48gpio->ack_lock);
- spin_lock(&idi48gpio->lock);
+ raw_spin_lock(&idi48gpio->lock);
cos_status = inb(idi48gpio->base + 7);
- spin_unlock(&idi48gpio->lock);
+ raw_spin_unlock(&idi48gpio->lock);
/* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */
if (cos_status & BIT(6)) {
@@ -256,7 +258,7 @@ static int idi_48_probe(struct device *dev, unsigned int id)
idi48gpio->chip.get = idi_48_gpio_get;
idi48gpio->base = base[id];
- spin_lock_init(&idi48gpio->lock);
+ raw_spin_lock_init(&idi48gpio->lock);
spin_lock_init(&idi48gpio->ack_lock);
err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);