[PATCH] irqchip: vt8500: Properly mask the interrupt in irq_mask()

From: Axel Lin
Date: Mon Apr 28 2014 - 07:55:38 EST


Current code sets both irq_ack and irq_mask callbacks to vt8500_irq_mask().
However, vt8500_irq_mask does not clear interrupt enable bit when the interrupt
trigger mode is edge trigger.

This patch moves the code clearing Interrupt Status Register bit to irq_ack().
Make irq_mask() always clear interrupt enable bit for all interrupt trigger mode.

According to the datasheet, the Interrupt Status Register is written one to
clear(Write 0 has no effect). So we don't need a read-modify-write operation
for clearing a bit in interrupt status register.

Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
---
drivers/irqchip/irq-vt8500.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/irqchip/irq-vt8500.c b/drivers/irqchip/irq-vt8500.c
index d970595..eb6d05a 100644
--- a/drivers/irqchip/irq-vt8500.c
+++ b/drivers/irqchip/irq-vt8500.c
@@ -81,25 +81,24 @@ struct vt8500_irq_data {
static struct vt8500_irq_data intc[VT8500_INTC_MAX];
static u32 active_cnt = 0;

-static void vt8500_irq_mask(struct irq_data *d)
+static void vt8500_irq_ack(struct irq_data *d)
{
struct vt8500_irq_data *priv = d->domain->host_data;
void __iomem *base = priv->base;
void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4);
- u8 edge, dctr;
- u32 status;
-
- edge = readb(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
- if (edge) {
- status = readl(stat_reg);
-
- status |= (1 << (d->hwirq & 0x1f));
- writel(status, stat_reg);
- } else {
- dctr = readb(base + VT8500_ICDC + d->hwirq);
- dctr &= ~VT8500_INT_ENABLE;
- writeb(dctr, base + VT8500_ICDC + d->hwirq);
- }
+
+ writel(1 << (d->hwirq & 0x1f), stat_reg);
+}
+
+static void vt8500_irq_mask(struct irq_data *d)
+{
+ struct vt8500_irq_data *priv = d->domain->host_data;
+ void __iomem *base = priv->base;
+ u8 dctr;
+
+ dctr = readb(base + VT8500_ICDC + d->hwirq);
+ dctr &= ~VT8500_INT_ENABLE;
+ writeb(dctr, base + VT8500_ICDC + d->hwirq);
}

static void vt8500_irq_unmask(struct irq_data *d)
@@ -145,7 +144,7 @@ static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type)

static struct irq_chip vt8500_irq_chip = {
.name = "vt8500",
- .irq_ack = vt8500_irq_mask,
+ .irq_ack = vt8500_irq_ack,
.irq_mask = vt8500_irq_mask,
.irq_unmask = vt8500_irq_unmask,
.irq_set_type = vt8500_irq_set_type,
--
1.8.1.2



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