From 732063b92bb727b27e61580ce278dddefe31c6ad Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 17 Mar 2011 19:32:55 +0000 Subject: [PATCH] gpio/langwell: Simplify demux loop Use __ffs() to find the pending interrupt source instead of looping 32 times. Signed-off-by: Thomas Gleixner Cc: Feng Tang Cc: Alek Du Cc: Alan Cox Signed-off-by: Grant Likely --- drivers/gpio/langwell_gpio.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/gpio/langwell_gpio.c b/drivers/gpio/langwell_gpio.c index 6efc4e60aca7..f658af016f44 100644 --- a/drivers/gpio/langwell_gpio.c +++ b/drivers/gpio/langwell_gpio.c @@ -191,19 +191,20 @@ static void lnw_irq_handler(unsigned irq, struct irq_desc *desc) struct lnw_gpio *lnw = irq_data_get_irq_handler_data(data); struct irq_chip *chip = irq_data_get_irq_chip(data); u32 base, gpio, gedr_v; + unsigned long pending; void __iomem *gedr; /* check GPIO controller to check which pin triggered the interrupt */ for (base = 0; base < lnw->chip.ngpio; base += 32) { gedr = gpio_reg(&lnw->chip, base, GEDR); - gedr_v = readl(gedr); + gedr_v = pending = readl(gedr); if (!gedr_v) continue; - for (gpio = base; gpio < base + 32; gpio++) - if (gedr_v & BIT(gpio % 32)) { - pr_debug("pin %d triggered\n", gpio); - generic_handle_irq(lnw->irq_base + gpio); - } + while (pending) { + gpio = __ffs(pending) - 1; + pending &= ~BIT(gpio); + generic_handle_irq(lnw->irq_base + base + gpio); + } /* clear the edge detect status bit */ writel(gedr_v, gedr); } -- 2.20.1