[PATCH v2 2/2] ARM: omap4: gpio: add locking around calls to _set_gpio_triggering
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From: Colin Cross <hidden>
Date: 2011-06-06 20:38:46
Also in:
linux-omap, lkml
Subsystem:
gpio subsystem, omap gpio driver, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Grygorii Strashko, Santosh Shilimkar, Kevin Hilman, Linus Torvalds
_set_gpio_triggering uses read-modify-write on bank registers, lock bank->lock around all calls to it to prevent register corruption if two cpus access gpios in the same bank at the same time. Signed-off-by: Colin Cross <redacted> --- drivers/gpio/gpio-omap.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 8ba6957..b14bfd4 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c@@ -1126,8 +1126,11 @@ static void gpio_irq_shutdown(struct irq_data *d) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank = irq_data_get_irq_chip_data(d); + unsigned long flags; + spin_lock_irqsave(&bank->lock, flags); _reset_gpio(bank, gpio); + spin_unlock_irqrestore(&bank->lock, flags); } static void gpio_ack_irq(struct irq_data *d)
@@ -1142,9 +1145,12 @@ static void gpio_mask_irq(struct irq_data *d) { unsigned int gpio = d->irq - IH_GPIO_BASE; struct gpio_bank *bank = irq_data_get_irq_chip_data(d); + unsigned long flags; + spin_lock_irqsave(&bank->lock, flags); _set_gpio_irqenable(bank, gpio, 0); _set_gpio_triggering(bank, get_gpio_index(gpio), IRQ_TYPE_NONE); + spin_unlock_irqrestore(&bank->lock, flags); } static void gpio_unmask_irq(struct irq_data *d)
@@ -1153,7 +1159,9 @@ static void gpio_unmask_irq(struct irq_data *d) struct gpio_bank *bank = irq_data_get_irq_chip_data(d); unsigned int irq_mask = 1 << get_gpio_index(gpio); u32 trigger = irqd_get_trigger_type(d); + unsigned long flags; + spin_lock_irqsave(&bank->lock, flags); if (trigger) _set_gpio_triggering(bank, get_gpio_index(gpio), trigger);
@@ -1165,6 +1173,7 @@ static void gpio_unmask_irq(struct irq_data *d) } _set_gpio_irqenable(bank, gpio, 1); + spin_unlock_irqrestore(&bank->lock, flags); } static struct irq_chip gpio_irq_chip = {
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1.7.4.1