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authorGuenter Roeck <linux@roeck-us.net>2016-02-28 13:12:14 -0800
committerWim Van Sebroeck <wim@iguana.be>2016-03-16 21:11:07 +0100
commitfb32e9b9deeb5df2913deb7d2ae8c36f4f66ecf3 (patch)
tree26c4b592457a48ae5d175ece5aa37f1b94fb7f47 /Documentation/watchdog
parente21f56219bf636b4abd15a0b076a1c5cba381501 (diff)
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watchdog: Make set_timeout function optional
For some watchdogs, the watchdog driver handles timeout changes without explicitly setting any registers. In this situation, the watchdog driver might only set the 'timeout' variable but do nothing else. This can as well be handled by the infrastructure, so make the set_timeout callback optional. If WDIOF_SETTIMEOUT is configured but the .set_timeout callback is not available, update the timeout variable in the infrastructure code. 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.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 55120a055a14..dd8f912c0576 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -156,6 +156,11 @@ they are supported. These optional routines/operations are:
because the watchdog does not necessarily has a 1 second resolution).
(Note: the WDIOF_SETTIMEOUT 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.timeout, this callback can be omitted.
+ 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.
* 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.