Re: [PATCH] rtc: rtc-s3c: fix no occurrence of alarm interrupt

From: Andrew Morton
Date: Thu Sep 08 2011 - 19:53:20 EST


On Wed, 31 Aug 2011 19:21:50 +0900
Donggeun Kim <dg77.kim@xxxxxxxxxxx> wrote:

> The driver does not generate alarm interrupt
> even though time for alarm is set.
> This results from disabling rtc_clk after setting time for alarm.
> To generate alarm interrupt,
> the driver should maintain enabled state for rtc_clk
> until alarm interrupt occurs.
> This patch allows to generate alarm interrupt.
>
> ...
>
> +static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);
> +
> +static void s3c_rtc_alarm_clk_enable(bool enable)
> +{
> + static bool alarm_clk_enabled;
> + unsigned long irq_flags;
> +
> + spin_lock_irqsave(&s3c_rtc_alarm_clk_lock, irq_flags);
> + if (enable) {
> + if (!alarm_clk_enabled) {
> + clk_enable(rtc_clk);
> + alarm_clk_enabled = true;
> + }
> + } else {
> + if (alarm_clk_enabled) {
> + clk_disable(rtc_clk);
> + alarm_clk_enabled = false;
> + }
> + }
> + spin_unlock_irqrestore(&s3c_rtc_alarm_clk_lock, irq_flags);
> +}

s3c_rtc_alarm_clk_lock is only used within s3c_rtc_alarm_clk_enable(),
so we can reduce its scope:

--- a/drivers/rtc/rtc-s3c.c~rtc-rtc-s3c-fix-no-occurrence-of-alarm-interrupt-fix
+++ a/drivers/rtc/rtc-s3c.c
@@ -50,10 +50,10 @@ static bool wake_en;
static enum s3c_cpu_type s3c_rtc_cpu_type;

static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
-static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);

static void s3c_rtc_alarm_clk_enable(bool enable)
{
+ static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);
static bool alarm_clk_enabled;
unsigned long irq_flags;

_

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