ALSA: asihpi - Fix imbalanced lock path in hw_message

[safe/jmp/linux-2.6] / lib / ratelimit.c

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 0e2c28e..027a03f 100644 (file)
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -9,18 +9,23 @@
  * This file is released under the GPLv2.
  */
 
-#include <linux/kernel.h>
+#include <linux/ratelimit.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
 
 /*
  * __ratelimit - rate limiting
  * @rs: ratelimit_state data
+ * @func: name of calling function
  *
- * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
- * in every @rs->ratelimit_jiffies
+ * This enforces a rate limit: not more than @rs->burst callbacks
+ * in every @rs->interval
+ *
+ * RETURNS:
+ * 0 means callbacks will be suppressed.
+ * 1 means go ahead and do it.
  */
-int __ratelimit(struct ratelimit_state *rs)
+int ___ratelimit(struct ratelimit_state *rs, const char *func)
 {
        unsigned long flags;
        int ret;
@@ -28,14 +33,22 @@ int __ratelimit(struct ratelimit_state *rs)
        if (!rs->interval)
                return 1;
 
-       spin_lock_irqsave(&rs->lock, flags);
+       /*
+        * If we contend on this state's lock then almost
+        * by definition we are too busy to print a message,
+        * in addition to the one that will be printed by
+        * the entity that is holding the lock already:
+        */
+       if (!spin_trylock_irqsave(&rs->lock, flags))
+               return 0;
+
        if (!rs->begin)
                rs->begin = jiffies;
 
        if (time_is_before_jiffies(rs->begin + rs->interval)) {
                if (rs->missed)
                        printk(KERN_WARNING "%s: %d callbacks suppressed\n",
-                               __func__, rs->missed);
+                               func, rs->missed);
                rs->begin   = 0;
                rs->printed = 0;
                rs->missed  = 0;
@@ -51,4 +64,4 @@ int __ratelimit(struct ratelimit_state *rs)
 
        return ret;
 }
-EXPORT_SYMBOL(__ratelimit);
+EXPORT_SYMBOL(___ratelimit);