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authorWolfram Sang <wsa+renesas@sang-engineering.com>2017-02-07 15:03:29 +0100
committerGuenter Roeck <linux@roeck-us.net>2017-02-24 23:00:23 +0100
commit4cbc69023a2129c271ed67da555d62eca42469d2 (patch)
treedfeff856480f7d1cd018f3e6b8c90b470fa53967
parentwatchdog: zx2967: add watchdog controller driver for ZTE's zx2967 family (diff)
downloadlinux-4cbc69023a2129c271ed67da555d62eca42469d2.tar.xz
linux-4cbc69023a2129c271ed67da555d62eca42469d2.zip
watchdog: softdog: make pretimeout support a compile option
It occurred to me that the panic pretimeout governor will stall the softdog, because it is purely software which simply breaks when the kernel panics. Testing governors with the softdog on the other hand is really useful, so make this feature a compile time option which nees to be enabled explicitly. This also removes the overhead if pretimeout support is not used because it will now be compiled away (saving ~10% on ARM32). Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
-rw-r--r--drivers/watchdog/Kconfig8
-rw-r--r--drivers/watchdog/softdog.c21
2 files changed, 21 insertions, 8 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 2d006d8cfb15..1a4d6ca8028d 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -71,6 +71,14 @@ config SOFT_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called softdog.
+config SOFT_WATCHDOG_PRETIMEOUT
+ bool "Software watchdog pretimeout governor support"
+ depends on SOFT_WATCHDOG && WATCHDOG_PRETIMEOUT_GOV
+ help
+ Enable this if you want to use pretimeout governors with the software
+ watchdog. Be aware that governors might affect the watchdog because it
+ is purely software, e.g. the panic governor will stall it!
+
config DA9052_WATCHDOG
tristate "Dialog DA9052 Watchdog"
depends on PMIC_DA9052 || COMPILE_TEST
diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
index c7bdc986dca1..7983029852ab 100644
--- a/drivers/watchdog/softdog.c
+++ b/drivers/watchdog/softdog.c
@@ -87,11 +87,13 @@ static int softdog_ping(struct watchdog_device *w)
if (!mod_timer(&softdog_ticktock, jiffies + (w->timeout * HZ)))
__module_get(THIS_MODULE);
- if (w->pretimeout)
- mod_timer(&softdog_preticktock, jiffies +
- (w->timeout - w->pretimeout) * HZ);
- else
- del_timer(&softdog_preticktock);
+ if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT)) {
+ if (w->pretimeout)
+ mod_timer(&softdog_preticktock, jiffies +
+ (w->timeout - w->pretimeout) * HZ);
+ else
+ del_timer(&softdog_preticktock);
+ }
return 0;
}
@@ -101,15 +103,15 @@ static int softdog_stop(struct watchdog_device *w)
if (del_timer(&softdog_ticktock))
module_put(THIS_MODULE);
- del_timer(&softdog_preticktock);
+ if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT))
+ del_timer(&softdog_preticktock);
return 0;
}
static struct watchdog_info softdog_info = {
.identity = "Software Watchdog",
- .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
- WDIOF_PRETIMEOUT,
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops softdog_ops = {
@@ -134,6 +136,9 @@ static int __init softdog_init(void)
watchdog_set_nowayout(&softdog_dev, nowayout);
watchdog_stop_on_reboot(&softdog_dev);
+ if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT))
+ softdog_info.options |= WDIOF_PRETIMEOUT;
+
ret = watchdog_register_device(&softdog_dev);
if (ret)
return ret;