rtc-ds1742: fix races around device registration

[safe/jmp/linux-2.6] / drivers / rtc / rtc-coh901331.c

diff --git a/drivers/rtc/rtc-coh901331.c b/drivers/rtc/rtc-coh901331.c
index 7fe1fa2..03ea530 100644 (file)
--- a/drivers/rtc/rtc-coh901331.c
+++ b/drivers/rtc/rtc-coh901331.c
@@ -58,7 +58,16 @@ static irqreturn_t coh901331_interrupt(int irq, void *data)
        clk_enable(rtap->clk);
        /* Ack IRQ */
        writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
+       /*
+        * Disable the interrupt. This is necessary because
+        * the RTC lives on a lower-clocked line and will
+        * not release the IRQ line until after a few (slower)
+        * clock cycles. The interrupt will be re-enabled when
+        * a new alarm is set anyway.
+        */
+       writel(0, rtap->virtbase + COH901331_IRQ_MASK);
        clk_disable(rtap->clk);
+
        /* Set alarm flag */
        rtc_update_irq(rtap->rtc, 1, RTC_AF);
 
@@ -128,6 +137,8 @@ static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
        else
                writel(0, rtap->virtbase + COH901331_IRQ_MASK);
        clk_disable(rtap->clk);
+
+       return 0;
 }
 
 static struct rtc_class_ops coh901331_ops = {