ipmi_watchdog: restore settings when BMC reset

If the BMC gets reset, it will return 0x80 response errors.

In less than a week
# grep "Error 80 on cmd 22" /var/log/kernel |wc -l
378681

In this case, it is probably a good idea to restore the IPMI settings.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Reported-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 3 deletions

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index c2917ffad2c2..34767a6d7f42 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -139,6 +139,8 @@
 #define IPMI_WDOG_SET_TIMER             0x24
 #define IPMI_WDOG_GET_TIMER             0x25
 
+#define IPMI_WDOG_TIMER_NOT_INIT_RESP   0x80
+
 /* These are here until the real ones get into the watchdog.h interface. */
 #ifndef WDIOC_GETTIMEOUT
 #define WDIOC_GETTIMEOUT        _IOW(WATCHDOG_IOCTL_BASE, 20, int)
@@ -596,6 +598,7 @@ static int ipmi_heartbeat(void)
         struct kernel_ipmi_msg            msg;
         int                               rv;
         struct ipmi_system_interface_addr addr;
+        int                               timeout_retries = 0;
 
         if (ipmi_ignore_heartbeat)
                 return 0;
@@ -616,6 +619,7 @@ static int ipmi_heartbeat(void)
 
         mutex_lock(&heartbeat_lock);
 
+restart:
         atomic_set(&heartbeat_tofree, 2);
 
         /*
@@ -653,7 +657,33 @@ static int ipmi_heartbeat(void)
         /* Wait for the heartbeat to be sent. */
         wait_for_completion(&heartbeat_wait);
 
-        if (heartbeat_recv_msg.msg.data[0] != 0) {
+        if (heartbeat_recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)  {
+                timeout_retries++;
+                if (timeout_retries > 3) {
+                        printk(KERN_ERR PFX ": Unable to restore the IPMI"
+                               " watchdog's settings, giving up.\n");
+                        rv = -EIO;
+                        goto out_unlock;
+                }
+
+                /*
+                 * The timer was not initialized, that means the BMC was
+                 * probably reset and lost the watchdog information.  Attempt
+                 * to restore the timer's info.  Note that we still hold
+                 * the heartbeat lock, to keep a heartbeat from happening
+                 * in this process, so must say no heartbeat to avoid a
+                 * deadlock on this mutex.
+                 */
+                rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
+                if (rv) {
+                        printk(KERN_ERR PFX ": Unable to send the command to"
+                               " set the watchdog's settings, giving up.\n");
+                        goto out_unlock;
+                }
+
+                /* We might need a new heartbeat, so do it now */
+                goto restart;
+        } else if (heartbeat_recv_msg.msg.data[0] != 0) {
                 /*
                  * Got an error in the heartbeat response.  It was already
                  * reported in ipmi_wdog_msg_handler, but we should return
@@ -662,6 +692,7 @@ static int ipmi_heartbeat(void)
                 rv = -EINVAL;
         }
 
+out_unlock:
         mutex_unlock(&heartbeat_lock);
 
         return rv;
@@ -922,11 +953,15 @@ static struct miscdevice ipmi_wdog_miscdev = {
 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
                                   void                 *handler_data)
 {
-        if (msg->msg.data[0] != 0) {
+        if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&
+                        msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)
+                printk(KERN_INFO PFX "response: The IPMI controller appears"
+                       " to have been reset, will attempt to reinitialize"
+                       " the watchdog timer\n");
+        else if (msg->msg.data[0] != 0)
                 printk(KERN_ERR PFX "response: Error %x on cmd %x\n",
                        msg->msg.data[0],
                        msg->msg.cmd);
-        }
 
         ipmi_free_recv_msg(msg);
 }