ipmi/watchdog: fix wdog hang on panic waiting for ipmi response

[ Upstream commit 2c1175c2e8e5487233cabde358a19577562ac83e ]

Commit c49c097610fe ("ipmi: Don't call receive handler in the
panic context") means that the panic_recv_free is not called during a
panic and the atomic count does not drop to 0.

Fix this by only expecting one decrement of the atomic variable
which comes from panic_smi_free.

Signed-off-by: Robert Lippert <rlippert@google.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index 40d400f..4ada103 100644 (file)
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -515,7 +515,7 @@ static void panic_halt_ipmi_heartbeat(void)
        msg.cmd = IPMI_WDOG_RESET_TIMER;
        msg.data = NULL;
        msg.data_len = 0;
-       atomic_add(2, &panic_done_count);
+       atomic_add(1, &panic_done_count);
        rv = ipmi_request_supply_msgs(watchdog_user,
                                      (struct ipmi_addr *) &addr,
                                      0,
@@ -525,7 +525,7 @@ static void panic_halt_ipmi_heartbeat(void)
                                      &panic_halt_heartbeat_recv_msg,
                                      1);
        if (rv)
-               atomic_sub(2, &panic_done_count);
+               atomic_sub(1, &panic_done_count);
 }
 
 static struct ipmi_smi_msg panic_halt_smi_msg = {
@@ -549,12 +549,12 @@ static void panic_halt_ipmi_set_timeout(void)
        /* Wait for the messages to be free. */
        while (atomic_read(&panic_done_count) != 0)
                ipmi_poll_interface(watchdog_user);
-       atomic_add(2, &panic_done_count);
+       atomic_add(1, &panic_done_count);
        rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
                                &panic_halt_recv_msg,
                                &send_heartbeat_now);
        if (rv) {
-               atomic_sub(2, &panic_done_count);
+               atomic_sub(1, &panic_done_count);
                printk(KERN_WARNING PFX
                       "Unable to extend the watchdog timeout.");
        } else {