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authorDoug Anderson <dianders@chromium.org>2013-11-25 15:36:43 -0800
committerWim Van Sebroeck <wim@iguana.be>2014-01-28 21:22:38 +0100
commit0f1dd98d896efb956d474754b5d2f0c420d40192 (patch)
treec4d2621fc2fa49f73407a068f5a99577b45e0598 /drivers/watchdog
parent25134eafb05eef6dd4b6caee3a711b63ee0c3737 (diff)
downloadop-kernel-dev-0f1dd98d896efb956d474754b5d2f0c420d40192.zip
op-kernel-dev-0f1dd98d896efb956d474754b5d2f0c420d40192.tar.gz
watchdog: s3c2410_wdt: Only register for cpufreq on ARM_S3C24XX_CPUFREQ
On modern SoCs the watchdog timer is parented on a clock that doesn't change every time we have a cpufreq change. That means we don't need to constantly adjust the watchdog timer, so avoid registering for and dealing with cpufreq transitions unless we've actually got CONFIG_ARM_S3C24XX_CPUFREQ defined. Note that this is more than just an optimization. The s3c2410 watchdog driver actually pats the watchdog on every CPU frequency change. On modern systems these happen many times per second (even in a system where "nothing" is happening). That effectively makes any userspace watchdog program useless (the watchdog is constantly patted by the kernel). If we need ARM_S3C24XX_CPUFREQ defined on a multiplatform kernel we'll need to make sure that kernel supports common clock and change this to user common clock framework. Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Tomasz Figa <t.figa@samsung.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/s3c2410_wdt.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 7d8fd04..c1ada33 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -264,7 +264,7 @@ static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
return IRQ_HANDLED;
}
-#ifdef CONFIG_CPU_FREQ
+#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
unsigned long val, void *data)
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