Messages in this thread Patch in this message | | | Date | Thu, 17 Mar 2011 19:32:55 -0000 | From | Thomas Gleixner <> | Subject | [patch 4/5] gpio: langwell: Simplify demux loop |
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Use __ffs() to find the pending interrupt source instead of looping 32 times.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Feng Tang <feng.tang@intel.com> Cc: Alek Du <alek.du@intel.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
--- drivers/gpio/langwell_gpio.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
Index: linux-2.6-tip/drivers/gpio/langwell_gpio.c =================================================================== --- linux-2.6-tip.orig/drivers/gpio/langwell_gpio.c +++ linux-2.6-tip/drivers/gpio/langwell_gpio.c @@ -191,19 +191,20 @@ static void lnw_irq_handler(unsigned irq 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); }
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