ipmi: Fix handling of BMC flags

The handling of BMC flags wasn't quite right in a few places, mainly
around enabling and disabling interrupts in the BMC.  Clean up the
code and fix the handling of the flags.

Signed-off-by: Corey Minyard <cminyard@mvista.com>

1 files changed, 68 insertions, 37 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index d1c44fd17aa8..e36487db0e94 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -328,7 +328,10 @@ static void deliver_recv_msg(struct smi_info *smi_info,
                              struct ipmi_smi_msg *msg)
 {
         /* Deliver the message to the upper layer. */
-        ipmi_smi_msg_received(smi_info->intf, msg);
+        if (smi_info->intf)
+                ipmi_smi_msg_received(smi_info->intf, msg);
+        else
+                ipmi_free_smi_msg(msg);
 }
 
 static void return_hosed_msg(struct smi_info *smi_info, int cCode)
@@ -436,6 +439,32 @@ static void start_clear_flags(struct smi_info *smi_info)
         smi_info->si_state = SI_CLEARING_FLAGS;
 }
 
+static void start_getting_msg_queue(struct smi_info *smi_info)
+{
+        smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
+        smi_info->curr_msg->data[1] = IPMI_GET_MSG_CMD;
+        smi_info->curr_msg->data_size = 2;
+
+        smi_info->handlers->start_transaction(
+                smi_info->si_sm,
+                smi_info->curr_msg->data,
+                smi_info->curr_msg->data_size);
+        smi_info->si_state = SI_GETTING_MESSAGES;
+}
+
+static void start_getting_events(struct smi_info *smi_info)
+{
+        smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
+        smi_info->curr_msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
+        smi_info->curr_msg->data_size = 2;
+
+        smi_info->handlers->start_transaction(
+                smi_info->si_sm,
+                smi_info->curr_msg->data,
+                smi_info->curr_msg->data_size);
+        smi_info->si_state = SI_GETTING_EVENTS;
+}
+
 static void smi_mod_timer(struct smi_info *smi_info, unsigned long new_val)
 {
         smi_info->last_timeout_jiffies = jiffies;
@@ -449,22 +478,45 @@ static void smi_mod_timer(struct smi_info *smi_info, unsigned long new_val)
  * polled until we can allocate some memory.  Once we have some
  * memory, we will re-enable the interrupt.
  */
-static inline void disable_si_irq(struct smi_info *smi_info)
+static inline bool disable_si_irq(struct smi_info *smi_info)
 {
         if ((smi_info->irq) && (!smi_info->interrupt_disabled)) {
                 start_disable_irq(smi_info);
                 smi_info->interrupt_disabled = true;
-                if (!atomic_read(&smi_info->stop_operation))
-                        smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
+                return true;
         }
+        return false;
 }
 
-static inline void enable_si_irq(struct smi_info *smi_info)
+static inline bool enable_si_irq(struct smi_info *smi_info)
 {
         if ((smi_info->irq) && (smi_info->interrupt_disabled)) {
                 start_enable_irq(smi_info);
                 smi_info->interrupt_disabled = false;
+                return true;
         }
+        return false;
+}
+
+/*
+ * Allocate a message.  If unable to allocate, start the interrupt
+ * disable process and return NULL.  If able to allocate but
+ * interrupts are disabled, free the message and return NULL after
+ * starting the interrupt enable process.
+ */
+static struct ipmi_smi_msg *alloc_msg_handle_irq(struct smi_info *smi_info)
+{
+        struct ipmi_smi_msg *msg;
+
+        msg = ipmi_alloc_smi_msg();
+        if (!msg) {
+                if (!disable_si_irq(smi_info))
+                        smi_info->si_state = SI_NORMAL;
+        } else if (enable_si_irq(smi_info)) {
+                ipmi_free_smi_msg(msg);
+                msg = NULL;
+        }
+        return msg;
 }
 
 static void handle_flags(struct smi_info *smi_info)
@@ -476,45 +528,22 @@ static void handle_flags(struct smi_info *smi_info)
 
                 start_clear_flags(smi_info);
                 smi_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
-                ipmi_smi_watchdog_pretimeout(smi_info->intf);
+                if (smi_info->intf)
+                        ipmi_smi_watchdog_pretimeout(smi_info->intf);
         } else if (smi_info->msg_flags & RECEIVE_MSG_AVAIL) {
                 /* Messages available. */
-                smi_info->curr_msg = ipmi_alloc_smi_msg();
-                if (!smi_info->curr_msg) {
-                        disable_si_irq(smi_info);
-                        smi_info->si_state = SI_NORMAL;
+                smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
+                if (!smi_info->curr_msg)
                         return;
-                }
-                enable_si_irq(smi_info);
 
-                smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
-                smi_info->curr_msg->data[1] = IPMI_GET_MSG_CMD;
-                smi_info->curr_msg->data_size = 2;
-
-                smi_info->handlers->start_transaction(
-                        smi_info->si_sm,
-                        smi_info->curr_msg->data,
-                        smi_info->curr_msg->data_size);
-                smi_info->si_state = SI_GETTING_MESSAGES;
+                start_getting_msg_queue(smi_info);
         } else if (smi_info->msg_flags & EVENT_MSG_BUFFER_FULL) {
                 /* Events available. */
-                smi_info->curr_msg = ipmi_alloc_smi_msg();
-                if (!smi_info->curr_msg) {
-                        disable_si_irq(smi_info);
-                        smi_info->si_state = SI_NORMAL;
+                smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
+                if (!smi_info->curr_msg)
                         return;
-                }
-                enable_si_irq(smi_info);
 
-                smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
-                smi_info->curr_msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
-                smi_info->curr_msg->data_size = 2;
-
-                smi_info->handlers->start_transaction(
-                        smi_info->si_sm,
-                        smi_info->curr_msg->data,
-                        smi_info->curr_msg->data_size);
-                smi_info->si_state = SI_GETTING_EVENTS;
+                start_getting_events(smi_info);
         } else if (smi_info->msg_flags & OEM_DATA_AVAIL &&
                    smi_info->oem_data_avail_handler) {
                 if (smi_info->oem_data_avail_handler(smi_info))
@@ -709,7 +738,9 @@ static void handle_transaction_done(struct smi_info *smi_info)
                                  "Maybe ok, but ipmi might run very slowly.\n");
                 } else
                         smi_info->interrupt_disabled = false;
-                smi_info->si_state = SI_NORMAL;
+
+                /* We enabled interrupts, flags may be pending. */
+                handle_flags(smi_info);
                 break;
         }