diff mbox

[V2,5/6] mpcore_wdt: Add cpufreq notifier to reload counter

Message ID 1309892440-3260-6-git-send-email-vkuzmichev@mvista.com (mailing list archive)
State New, archived
Headers show

Commit Message

vkuzmichev@mvista.com July 5, 2011, 7 p.m. UTC
In the case if CPU frequency is changed when watchdog is working it begins to
acount faster or slower. To avoid watchdog triggering before the margin time
the watchdog counter needs to be reloaded.

Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com>
---
 drivers/watchdog/mpcore_wdt.c |   31 ++++++++++++++++++++++++++++++-
 1 files changed, 30 insertions(+), 1 deletions(-)

Comments

Sergei Shtylyov July 6, 2011, 12:09 p.m. UTC | #1
Hello.

On 05-07-2011 23:00, Vitaly Kuzmichev wrote:

> In the case if CPU frequency is changed when watchdog is working it begins to
> acount faster or slower. To avoid watchdog triggering before the margin time
> the watchdog counter needs to be reloaded.

> Signed-off-by: Vitaly Kuzmichev<vkuzmichev@mvista.com>
> ---
>   drivers/watchdog/mpcore_wdt.c |   31 ++++++++++++++++++++++++++++++-
>   1 files changed, 30 insertions(+), 1 deletions(-)

> diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
> index 11c70df..38b9119 100644
> --- a/drivers/watchdog/mpcore_wdt.c
> +++ b/drivers/watchdog/mpcore_wdt.c
[...]
> @@ -426,6 +427,25 @@ static int __devexit mpcore_wdt_remove(struct platform_device *dev)
>   	return 0;
>   }
>
> +static int mpcore_wdt_notify(struct notifier_block *nb,
> +				unsigned long state, void *data)
> +{
> +	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);

    Need empty line here...

> +	/*
> +	 * The mpcore_wdt counter register must be reloaded to account
> +	 * properly with the new frequency.
> +	 */
> +	if (mpcore_wdt_dev&&  wdt&&  (state == CPUFREQ_POSTCHANGE ||
> +					state == CPUFREQ_RESUMECHANGE))
> +		mpcore_wdt_keepalive(wdt);
> +
> +	return NOTIFY_OK;
> +}
> +
> +static struct notifier_block mpcore_wdt_nb = {
> +	.notifier_call = mpcore_wdt_notify,
> +};
> +
>   /* work with hotplug and coldplug */
>   MODULE_ALIAS("platform:mpcore_wdt");
>
> @@ -444,6 +464,7 @@ static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. "
>
>   static int __init mpcore_wdt_init(void)
>   {
> +	int ret = 0;

    ... and here.

>   	/*
>   	 * Check that the margin value is within it's range;
>   	 * if not reset to the default

WBR, Sergei
diff mbox

Patch

diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
index 11c70df..38b9119 100644
--- a/drivers/watchdog/mpcore_wdt.c
+++ b/drivers/watchdog/mpcore_wdt.c
@@ -32,6 +32,7 @@ 
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/cpufreq.h>
 
 unsigned long twd_timer_get_rate(void);
 
@@ -426,6 +427,25 @@  static int __devexit mpcore_wdt_remove(struct platform_device *dev)
 	return 0;
 }
 
+static int mpcore_wdt_notify(struct notifier_block *nb,
+				unsigned long state, void *data)
+{
+	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
+	/*
+	 * The mpcore_wdt counter register must be reloaded to account
+	 * properly with the new frequency.
+	 */
+	if (mpcore_wdt_dev && wdt && (state == CPUFREQ_POSTCHANGE ||
+					state == CPUFREQ_RESUMECHANGE))
+		mpcore_wdt_keepalive(wdt);
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block mpcore_wdt_nb = {
+	.notifier_call = mpcore_wdt_notify,
+};
+
 /* work with hotplug and coldplug */
 MODULE_ALIAS("platform:mpcore_wdt");
 
@@ -444,6 +464,7 @@  static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. "
 
 static int __init mpcore_wdt_init(void)
 {
+	int ret = 0;
 	/*
 	 * Check that the margin value is within it's range;
 	 * if not reset to the default
@@ -456,11 +477,19 @@  static int __init mpcore_wdt_init(void)
 
 	printk(banner, mpcore_noboot, mpcore_margin, nowayout);
 
-	return platform_driver_register(&mpcore_wdt_driver);
+	ret = platform_driver_register(&mpcore_wdt_driver);
+
+	if (!ret)
+		ret = cpufreq_register_notifier(&mpcore_wdt_nb,
+						CPUFREQ_TRANSITION_NOTIFIER);
+
+	return ret;
 }
 
 static void __exit mpcore_wdt_exit(void)
 {
+	cpufreq_unregister_notifier(&mpcore_wdt_nb,
+					CPUFREQ_TRANSITION_NOTIFIER);
 	platform_driver_unregister(&mpcore_wdt_driver);
 }