3 files changed, 59 insertions, 52 deletions

diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 4252697a95d6..8e5b3488b370 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -60,6 +60,12 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     slots       - Reserve the slot index for the given driver.
                   This option takes multiple strings.           
                   See "Module Autoloading Support" section for details.
+    debug       - Specifies the debug message level
+                  (0 = disable debug prints, 1 = normal debug messages,
+                   2 = verbose debug messages)
+                  This option appears only when CONFIG_SND_DEBUG=y.
+                  This option can be dynamically changed via sysfs
+                  /sys/modules/snd/parameters/debug file.
   
   Module snd-pcm-oss
   ------------------
diff --git a/include/sound/core.h b/include/sound/core.h
index 309cb9659a05..a89728db5584 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -340,18 +340,17 @@ unsigned int snd_dma_pointer(unsigned long dma, unsigned int size);
 struct resource;
 void release_and_free_resource(struct resource *res);
 
-#ifdef CONFIG_SND_VERBOSE_PRINTK
-void snd_verbose_printk(const char *file, int line, const char *format, ...)
-     __attribute__ ((format (printf, 3, 4)));
-#endif
-#if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_VERBOSE_PRINTK)
-void snd_verbose_printd(const char *file, int line, const char *format, ...)
-     __attribute__ ((format (printf, 3, 4)));
-#endif
-
 /* --- */
 
-#ifdef CONFIG_SND_VERBOSE_PRINTK
+#if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
+void __snd_printk(unsigned int level, const char *file, int line,
+                  const char *format, ...)
+     __attribute__ ((format (printf, 4, 5)));
+#else
+#define __snd_printk(level, file, line, format, args...) \
+        prinkt(format, ##args)
+#endif
+
 /**
  * snd_printk - printk wrapper
  * @fmt: format string
@@ -360,15 +359,9 @@ void snd_verbose_printd(const char *file, int line, const char *format, ...)
  * when configured with CONFIG_SND_VERBOSE_PRINTK.
  */
 #define snd_printk(fmt, args...) \
-        snd_verbose_printk(__FILE__, __LINE__, fmt ,##args)
-#else
-#define snd_printk(fmt, args...) \
-        printk(fmt ,##args)
-#endif
+        __snd_printk(0, __FILE__, __LINE__, fmt, ##args)
 
 #ifdef CONFIG_SND_DEBUG
-
-#ifdef CONFIG_SND_VERBOSE_PRINTK
 /**
  * snd_printd - debug printk
  * @fmt: format string
@@ -377,11 +370,7 @@ void snd_verbose_printd(const char *file, int line, const char *format, ...)
  * Ignored when CONFIG_SND_DEBUG is not set.
  */
 #define snd_printd(fmt, args...) \
-        snd_verbose_printd(__FILE__, __LINE__, fmt ,##args)
-#else
-#define snd_printd(fmt, args...) \
-        printk(fmt ,##args)
-#endif
+        __snd_printk(1, __FILE__, __LINE__, fmt, ##args)
 
 /**
  * snd_BUG - give a BUG warning message and stack trace
@@ -428,9 +417,10 @@ static inline int __snd_bug_on(int cond)
  * Works like snd_printk() for debugging purposes.
  * Ignored when CONFIG_SND_DEBUG_VERBOSE is not set.
  */
-#define snd_printdd(format, args...) snd_printk(format, ##args)
+#define snd_printdd(format, args...) \
+        __snd_printk(2, __FILE__, __LINE__, format, ##args)
 #else
-#define snd_printdd(format, args...) /* nothing */
+#define snd_printdd(format, args...)    do { } while (0)
 #endif
 
 
diff --git a/sound/core/misc.c b/sound/core/misc.c
index 1d29e678369e..23a032c6d487 100644
--- a/sound/core/misc.c
+++ b/sound/core/misc.c
@@ -24,6 +24,20 @@
 #include <linux/ioport.h>
 #include <sound/core.h>
 
+#ifdef CONFIG_SND_DEBUG
+
+#ifdef CONFIG_SND_DEBUG_VERBOSE
+#define DEFAULT_DEBUG_LEVEL     2
+#else
+#define DEFAULT_DEBUG_LEVEL     1
+#endif
+
+static int debug = DEFAULT_DEBUG_LEVEL;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Debug level (0 = disable)");
+
+#endif /* CONFIG_SND_DEBUG */
+
 void release_and_free_resource(struct resource *res)
 {
         if (res) {
@@ -35,6 +49,7 @@ void release_and_free_resource(struct resource *res)
 EXPORT_SYMBOL(release_and_free_resource);
 
 #ifdef CONFIG_SND_VERBOSE_PRINTK
+/* strip the leading path if the given path is absolute */
 static const char *sanity_file_name(const char *path)
 {
         if (*path == '/')
@@ -43,48 +58,44 @@ static const char *sanity_file_name(const char *path)
                 return path;
 }
 
-void snd_verbose_printk(const char *path, int line, const char *format, ...)
+/* print file and line with a certain printk prefix */
+static int print_snd_pfx(unsigned int level, const char *path, int line,
+                         const char *format)
 {
         const char *file = sanity_file_name(path);
-        va_list args;
-        
-        if (format[0] == '<' && format[1] >= '0' && format[1] <= '7' && format[2] == '>') {
-                char tmp[] = "<0>";
+        char tmp[] = "<0>";
+        const char *pfx = level ? KERN_DEBUG : KERN_DEFAULT;
+        int ret = 0;
+
+        if (format[0] == '<' && format[2] == '>') {
                 tmp[1] = format[1];
-                printk("%sALSA %s:%d: ", tmp, file, line);
-                format += 3;
-        } else {
-                printk("ALSA %s:%d: ", file, line);
+                pfx = tmp;
+                ret = 1;
         }
-        va_start(args, format);
-        vprintk(format, args);
-        va_end(args);
+        printk("%sALSA %s:%d: ", pfx, file, line);
+        return ret;
 }
-
-EXPORT_SYMBOL(snd_verbose_printk);
+#else
+#define print_snd_pfx(level, path, line, format)        0
 #endif
 
-#if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_VERBOSE_PRINTK)
-void snd_verbose_printd(const char *path, int line, const char *format, ...)
+#if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
+void __snd_printk(unsigned int level, const char *path, int line,
+                  const char *format, ...)
 {
-        const char *file = sanity_file_name(path);
         va_list args;
         
-        if (format[0] == '<' && format[1] >= '0' && format[1] <= '7' && format[2] == '>') {
-                char tmp[] = "<0>";
-                tmp[1] = format[1];
-                printk("%sALSA %s:%d: ", tmp, file, line);
-                format += 3;
-        } else {
-                printk(KERN_DEBUG "ALSA %s:%d: ", file, line);
-        }
+#ifdef CONFIG_SND_DEBUG 
+        if (debug < level)
+                return;
+#endif
         va_start(args, format);
+        if (print_snd_pfx(level, path, line, format))
+                format += 3; /* skip the printk level-prefix */
         vprintk(format, args);
         va_end(args);
-
 }
-
-EXPORT_SYMBOL(snd_verbose_printd);
+EXPORT_SYMBOL_GPL(__snd_printk);
 #endif
 
 #ifdef CONFIG_PCI