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author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2016-08-31 14:52:41 +0300 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2016-09-24 10:27:15 +0300 |
commit | df044e02206230c7d79a9aef96a6c087476f5533 (patch) | |
tree | e1e6868b6d5a86c588457dc2b8c90418a6c8f02c /Documentation/watchdog | |
parent | 68d4cb809ef84f9a0ea6a23c4c0dc0ae48355f78 (diff) | |
download | linux-df044e02206230c7d79a9aef96a6c087476f5533.tar.xz |
watchdog: add pretimeout support to the core
Since the watchdog framework centrializes the IOCTL interfaces of device
drivers now, SETPRETIMEOUT and GETPRETIMEOUT need to be added in the
common code.
Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[vzapolskiy: added conditional pretimeout sysfs attribute visibility]
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'Documentation/watchdog')
-rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index 7f31125c123e..3402dcad5b03 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -50,6 +50,7 @@ struct watchdog_device { const struct watchdog_ops *ops; unsigned int bootstatus; unsigned int timeout; + unsigned int pretimeout; unsigned int min_timeout; unsigned int max_timeout; unsigned int min_hw_heartbeat_ms; @@ -77,6 +78,7 @@ It contains following fields: * timeout: the watchdog timer's timeout value (in seconds). This is the time after which the system will reboot if user space does not send a heartbeat request if WDOG_ACTIVE is set. +* pretimeout: the watchdog timer's pretimeout value (in seconds). * min_timeout: the watchdog timer's minimum timeout value (in seconds). If set, the minimum configurable value for 'timeout'. * max_timeout: the watchdog timer's maximum timeout value (in seconds), @@ -121,6 +123,7 @@ struct watchdog_ops { int (*ping)(struct watchdog_device *); unsigned int (*status)(struct watchdog_device *); int (*set_timeout)(struct watchdog_device *, unsigned int); + int (*set_pretimeout)(struct watchdog_device *, unsigned int); unsigned int (*get_timeleft)(struct watchdog_device *); int (*restart)(struct watchdog_device *); void (*ref)(struct watchdog_device *) __deprecated; @@ -188,6 +191,23 @@ they are supported. These optional routines/operations are: If set_timeout is not provided but, WDIOF_SETTIMEOUT is set, the watchdog infrastructure updates the timeout value of the watchdog_device internally to the requested value. + If the pretimeout feature is used (WDIOF_PRETIMEOUT), then set_timeout must + also take care of checking if pretimeout is still valid and set up the timer + accordingly. This can't be done in the core without races, so it is the + duty of the driver. +* set_pretimeout: this routine checks and changes the pretimeout value of + the watchdog. It is optional because not all watchdogs support pretimeout + notification. The timeout value is not an absolute time, but the number of + seconds before the actual timeout would happen. It returns 0 on success, + -EINVAL for "parameter out of range" and -EIO for "could not write value to + the watchdog". A value of 0 disables pretimeout notification. + (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the + watchdog's info structure). + If the watchdog driver does not have to perform any action but setting the + watchdog_device.pretimeout, this callback can be omitted. That means if + set_pretimeout is not provided but WDIOF_PRETIMEOUT is set, the watchdog + infrastructure updates the pretimeout value of the watchdog_device internally + to the requested value. * get_timeleft: this routines returns the time that's left before a reset. * restart: this routine restarts the machine. It returns 0 on success or a negative errno code for failure. |