Commit 487e4e08 authored by Rasmus Villemoes's avatar Rasmus Villemoes Committed by Wim Van Sebroeck
Browse files

watchdog: introduce CONFIG_WATCHDOG_OPEN_TIMEOUT 



This allows setting a default value for the watchdog.open_timeout
commandline parameter via Kconfig.

Some BSPs allow remote updating of the kernel image and root file
system, but updating the bootloader requires physical access. Hence, if
one has a firmware update that requires relaxing the
watchdog.open_timeout a little, the value used must be baked into the
kernel image itself and cannot come from the u-boot environment via the
kernel command line.

Being able to set the initial value in .config doesn't change the fact
that the value on the command line, if present, takes precedence, and is
of course immensely useful for development purposes while one has
console acccess, as well as usable in the cases where one can make a
permanent update of the kernel command line.

Signed-off-by: default avatarRasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent 4d1c6a0e

Documentation/watchdog/watchdog-parameters.txt

+4 −4
Original line number Diff line number Diff line
@@ -11,10 +11,10 @@ modules. 
The watchdog core parameter watchdog.open_timeout is the maximum time,

in seconds, for which the watchdog framework will take care of pinging

a running hardware watchdog until userspace opens the corresponding

/dev/watchdogN device. A value of 0 (the default) means an infinite

timeout. Setting this to a non-zero value can be useful to ensure that

either userspace comes up properly, or the board gets reset and allows

fallback logic in the bootloader to try something else.

/dev/watchdogN device. A value of 0 means an infinite timeout. Setting

this to a non-zero value can be useful to ensure that either userspace

comes up properly, or the board gets reset and allows fallback logic

in the bootloader to try something else.





-------------------------------------------------

drivers/watchdog/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -58,6 +58,15 @@ config WATCHDOG_HANDLE_BOOT_ENABLED 
	  the watchdog on its own. Thus if your userspace does not start fast

	  enough your device will reboot.



config WATCHDOG_OPEN_TIMEOUT

	int "Timeout value for opening watchdog device"

	default 0

	help

	  The maximum time, in seconds, for which the watchdog framework takes

	  care of pinging a hardware watchdog.  A value of 0 means infinite. The

	  value set here can be overridden by the commandline parameter

	  "watchdog.open_timeout".



config WATCHDOG_SYSFS

	bool "Read different watchdog information through sysfs"

	help

drivers/watchdog/watchdog_dev.c

+3 −2
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ static struct kthread_worker *watchdog_kworker; 
static bool handle_boot_enabled =

	IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED);



static unsigned open_timeout;

static unsigned open_timeout = CONFIG_WATCHDOG_OPEN_TIMEOUT;



static bool watchdog_past_open_deadline(struct watchdog_core_data *data)

{
@@ -1214,4 +1214,5 @@ MODULE_PARM_DESC(handle_boot_enabled, 


module_param(open_timeout, uint, 0644);

MODULE_PARM_DESC(open_timeout,

	"Maximum time (in seconds, 0 means infinity) for userspace to take over a running watchdog (default=0)");
 
	"Maximum time (in seconds, 0 means infinity) for userspace to take over a running watchdog (default="

	__MODULE_STRING(CONFIG_WATCHDOG_OPEN_TIMEOUT) ")");

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