[PATCH] IPMI: watchdog handle panic properly

Modify the watchdog timeout in IPMI to only do things at panic/reboot time if
the watchdog timer was already running.  Some BIOSes do not disable the
watchdog timer at startup, and this led to a reboot a while later if the new
OS running didn't start monitoring the watchdog, even if the watchdog was not
running before.

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 10 insertions, 8 deletions

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index 8f8867170973..1a0a19c53605 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -949,9 +949,10 @@ static int wdog_reboot_handler(struct notifier_block *this,
                         /* Disable the WDT if we are shutting down. */
                         ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
                         panic_halt_ipmi_set_timeout();
-                } else {
+                } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
                         /* Set a long timer to let the reboot happens, but
-                           reboot if it hangs. */
+                           reboot if it hangs, but only if the watchdog
+                           timer was already running. */
                         timeout = 120;
                         pretimeout = 0;
                         ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
@@ -973,16 +974,17 @@ static int wdog_panic_handler(struct notifier_block *this,
 {
         static int panic_event_handled = 0;
 
-        /* On a panic, if we have a panic timeout, make sure that the thing
-           reboots, even if it hangs during that panic. */
-        if (watchdog_user && !panic_event_handled) {
-                /* Make sure the panic doesn't hang, and make sure we
-                   do this only once. */
+        /* On a panic, if we have a panic timeout, make sure to extend
+           the watchdog timer to a reasonable value to complete the
+           panic, if the watchdog timer is running.  Plus the
+           pretimeout is meaningless at panic time. */
+        if (watchdog_user && !panic_event_handled &&
+            ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
+                /* Make sure we do this only once. */
                 panic_event_handled = 1;
             
                 timeout = 255;
                 pretimeout = 0;
-                ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
                 panic_halt_ipmi_set_timeout();
         }