watchdog: WatchDog Timer Driver Core - Add WDIOC_KEEPALIVE ioctl

[deliverable/linux.git] / Documentation / watchdog / watchdog-kernel-api.txt

diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 2bdc6dc6e04c9fe1f6675c2bcc80762bf6620fb3..abbcf2ce8f62e9e1b86b8eaeae660e8eba8d2352 100644 (file)
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -101,6 +101,9 @@ they are supported. These optional routines/operations are:
   the watchdog timer driver core does: to send a keepalive ping to the watchdog
   timer hardware it will either use the ping operation (when available) or the
   start operation (when the ping operation is not available).
+  (Note: the WDIOC_KEEPALIVE ioctl call will only be active when the
+  WDIOF_KEEPALIVEPING bit has been set in the option field on the watchdog's
+  info structure).
 * status: this routine checks the status of the watchdog timer device. The
   status of the device is reported with watchdog WDIOF_* status flags/bits.