[PATCH v2 4/7] gpio: brcmstb: switch to handle_level_irq flow

From: Doug Berger
Date: Tue Oct 24 2017 - 15:56:00 EST


Reading and writing the gpio bank status register each time a pending
interrupt bit is serviced could cause new pending bits to be cleared
without servicing the associated interrupts.

By using the handle_level_irq flow instead of the handle_simple_irq
flow we get proper handling of interrupt masking as well as acking
of interrupts. The irq_ack method is added to support this.

Fixes: 19a7b6940b78 ("gpio: brcmstb: Add interrupt and wakeup source support")
Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Acked-by: Gregory Fong <gregory.0xf0@xxxxxxxxx>
---
drivers/gpio/gpio-brcmstb.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
index fd8c0412f8af..513de4936a25 100644
--- a/drivers/gpio/gpio-brcmstb.c
+++ b/drivers/gpio/gpio-brcmstb.c
@@ -114,6 +114,16 @@ static void brcmstb_gpio_irq_unmask(struct irq_data *d)
brcmstb_gpio_set_imask(bank, d->hwirq, true);
}

+static void brcmstb_gpio_irq_ack(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+ struct brcmstb_gpio_priv *priv = bank->parent_priv;
+ u32 mask = BIT(d->hwirq);
+
+ gc->write_reg(priv->reg_base + GIO_STAT(bank->id), mask);
+}
+
static int brcmstb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
@@ -217,21 +227,16 @@ static void brcmstb_gpio_irq_bank_handler(struct brcmstb_gpio_bank *bank)
{
struct brcmstb_gpio_priv *priv = bank->parent_priv;
struct irq_domain *irq_domain = bank->gc.irqdomain;
- void __iomem *reg_base = priv->reg_base;
unsigned long status;

while ((status = brcmstb_gpio_get_active_irqs(bank))) {
int bit;

for_each_set_bit(bit, &status, 32) {
- u32 stat = bank->gc.read_reg(reg_base +
- GIO_STAT(bank->id));
if (bit >= bank->width)
dev_warn(&priv->pdev->dev,
"IRQ for invalid GPIO (bank=%d, offset=%d)\n",
bank->id, bit);
- bank->gc.write_reg(reg_base + GIO_STAT(bank->id),
- stat | BIT(bit));
generic_handle_irq(irq_find_mapping(irq_domain, bit));
}
}
@@ -354,6 +359,7 @@ static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
bank->irq_chip.name = dev_name(dev);
bank->irq_chip.irq_mask = brcmstb_gpio_irq_mask;
bank->irq_chip.irq_unmask = brcmstb_gpio_irq_unmask;
+ bank->irq_chip.irq_ack = brcmstb_gpio_irq_ack;
bank->irq_chip.irq_set_type = brcmstb_gpio_irq_set_type;

/* Ensures that all non-wakeup IRQs are disabled at suspend */
@@ -394,7 +400,7 @@ static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
bank->irq_chip.irq_set_wake = brcmstb_gpio_irq_set_wake;

err = gpiochip_irqchip_add(&bank->gc, &bank->irq_chip, 0,
- handle_simple_irq, IRQ_TYPE_NONE);
+ handle_level_irq, IRQ_TYPE_NONE);
if (err)
return err;
gpiochip_set_chained_irqchip(&bank->gc, &bank->irq_chip,
--
2.14.1