ipmi: reduce polling when interrupts are available

If we're not currently in the middle of a transaction, and if we have
interrupts, there's no real reason to poll the controller more frequently
than the core IPMI code does.  Set the interrupt_disabled flag
appropriately as the interrupt state changes, and make the timeout code
reset itself only if the transaction is incomplete or we have no
interrupts.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 5b7bf7d22494379e9f902fbef99ef49b7a54b5aa..c8d68cf6859843b1d84ccb3a552fe006b17750e0 100644 (file)
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -454,6 +454,9 @@ static inline void 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 = 1;
+               if (!atomic_read(&smi_info->stop_operation))
+                       mod_timer(&smi_info->si_timer,
+                                 jiffies + SI_TIMEOUT_JIFFIES);
        }
 }
 
@@ -706,6 +709,8 @@ static void handle_transaction_done(struct smi_info *smi_info)
                        printk(KERN_WARNING
                               "ipmi_si: Could not enable interrupts"
                               ", failed set, using polled mode.\n");
+               } else {
+                       smi_info->interrupt_disabled = 0;
                }
                smi_info->si_state = SI_NORMAL;
                break;
@@ -886,6 +891,8 @@ static void sender(void                *send_info,
        printk("**Enqueue: %d.%9.9d\n", t.tv_sec, t.tv_usec);
 #endif
 
+       mod_timer(&smi_info->si_timer, jiffies + SI_TIMEOUT_JIFFIES);
+
        if (smi_info->run_to_completion) {
                /*
                 * If we are running to completion, then throw it in
@@ -1086,7 +1093,8 @@ static void smi_timeout(unsigned long data)
        }
 
  do_add_timer:
-       add_timer(&(smi_info->si_timer));
+       if ((smi_result != SI_SM_IDLE) || smi_info->interrupt_disabled)
+               add_timer(&(smi_info->si_timer));
 }
 
 static irqreturn_t si_irq_handler(int irq, void *data)
@@ -3117,7 +3125,7 @@ static int try_smi_init(struct smi_info *new_smi)
        for (i = 0; i < SI_NUM_STATS; i++)
                atomic_set(&new_smi->stats[i], 0);
 
-       new_smi->interrupt_disabled = 0;
+       new_smi->interrupt_disabled = 1;
        atomic_set(&new_smi->stop_operation, 0);
        new_smi->intf_num = smi_num;
        smi_num++;