Merge branch 'rio.b19' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/bird

[pandora-kernel.git] / kernel / printk.c

diff --git a/kernel/printk.c b/kernel/printk.c
index 2251be8..19a9556 100644 (file)
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -11,7 +11,7 @@
  * Ted Ts'o, 2/11/93.
  * Modified for sysctl support, 1/8/97, Chris Horn.
  * Fixed SMP synchronization, 08/08/99, Manfred Spraul
- *     manfreds@colorfullife.com
+ *     manfred@colorfullife.com
  * Rewrote bits to get rid of console_lock
  *     01Mar01 Andrew Morton <andrewm@uow.edu.au>
  */
@@ -67,6 +67,7 @@ EXPORT_SYMBOL(oops_in_progress);
  * driver system.
  */
 static DECLARE_MUTEX(console_sem);
+static DECLARE_MUTEX(secondary_console_sem);
 struct console *console_drivers;
 /*
  * This is used for debugging the mess that is the VT code by
@@ -76,7 +77,7 @@ struct console *console_drivers;
  * path in the console code where we end up in places I want
  * locked without the console sempahore held
  */
-static int console_locked;
+static int console_locked, console_suspended;
 
 /*
  * logbuf_lock protects log_buf, log_start, log_end, con_start and logged_chars
@@ -122,44 +123,6 @@ static char *log_buf = __log_buf;
 static int log_buf_len = __LOG_BUF_LEN;
 static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */
 
-/*
- *     Setup a list of consoles. Called from init/main.c
- */
-static int __init console_setup(char *str)
-{
-       char name[sizeof(console_cmdline[0].name)];
-       char *s, *options;
-       int idx;
-
-       /*
-        *      Decode str into name, index, options.
-        */
-       if (str[0] >= '0' && str[0] <= '9') {
-               strcpy(name, "ttyS");
-               strncpy(name + 4, str, sizeof(name) - 5);
-       } else
-               strncpy(name, str, sizeof(name) - 1);
-       name[sizeof(name) - 1] = 0;
-       if ((options = strchr(str, ',')) != NULL)
-               *(options++) = 0;
-#ifdef __sparc__
-       if (!strcmp(str, "ttya"))
-               strcpy(name, "ttyS0");
-       if (!strcmp(str, "ttyb"))
-               strcpy(name, "ttyS1");
-#endif
-       for (s = name; *s; s++)
-               if ((*s >= '0' && *s <= '9') || *s == ',')
-                       break;
-       idx = simple_strtoul(s, NULL, 10);
-       *s = 0;
-
-       add_preferred_console(name, idx, options);
-       return 1;
-}
-
-__setup("console=", console_setup);
-
 static int __init log_buf_len_setup(char *str)
 {
        unsigned long size = memparse(str, &str);
@@ -398,8 +361,7 @@ static void call_console_drivers(unsigned long start, unsigned long end)
        unsigned long cur_index, start_print;
        static int msg_level = -1;
 
-       if (((long)(start - end)) > 0)
-               BUG();
+       BUG_ON(((long)(start - end)) > 0);
 
        cur_index = start;
        start_print = start;
@@ -659,6 +621,44 @@ static void call_console_drivers(unsigned long start, unsigned long end)
 
 #endif
 
+/*
+ * Set up a list of consoles.  Called from init/main.c
+ */
+static int __init console_setup(char *str)
+{
+       char name[sizeof(console_cmdline[0].name)];
+       char *s, *options;
+       int idx;
+
+       /*
+        * Decode str into name, index, options.
+        */
+       if (str[0] >= '0' && str[0] <= '9') {
+               strcpy(name, "ttyS");
+               strncpy(name + 4, str, sizeof(name) - 5);
+       } else {
+               strncpy(name, str, sizeof(name) - 1);
+       }
+       name[sizeof(name) - 1] = 0;
+       if ((options = strchr(str, ',')) != NULL)
+               *(options++) = 0;
+#ifdef __sparc__
+       if (!strcmp(str, "ttya"))
+               strcpy(name, "ttyS0");
+       if (!strcmp(str, "ttyb"))
+               strcpy(name, "ttyS1");
+#endif
+       for (s = name; *s; s++)
+               if ((*s >= '0' && *s <= '9') || *s == ',')
+                       break;
+       idx = simple_strtoul(s, NULL, 10);
+       *s = 0;
+
+       add_preferred_console(name, idx, options);
+       return 1;
+}
+__setup("console=", console_setup);
+
 /**
  * add_preferred_console - add a device to the list of preferred consoles.
  * @name: device name
@@ -698,6 +698,23 @@ int __init add_preferred_console(char *name, int idx, char *options)
        return 0;
 }
 
+/**
+ * suspend_console - suspend the console subsystem
+ *
+ * This disables printk() while we go into suspend states
+ */
+void suspend_console(void)
+{
+       acquire_console_sem();
+       console_suspended = 1;
+}
+
+void resume_console(void)
+{
+       console_suspended = 0;
+       release_console_sem();
+}
+
 /**
  * acquire_console_sem - lock the console system for exclusive use.
  *
@@ -708,8 +725,11 @@ int __init add_preferred_console(char *name, int idx, char *options)
  */
 void acquire_console_sem(void)
 {
-       if (in_interrupt())
-               BUG();
+       BUG_ON(in_interrupt());
+       if (console_suspended) {
+               down(&secondary_console_sem);
+               return;
+       }
        down(&console_sem);
        console_locked = 1;
        console_may_schedule = 1;
@@ -752,6 +772,10 @@ void release_console_sem(void)
        unsigned long _con_start, _log_end;
        unsigned long wake_klogd = 0;
 
+       if (console_suspended) {
+               up(&secondary_console_sem);
+               return;
+       }
        for ( ; ; ) {
                spin_lock_irqsave(&logbuf_lock, flags);
                wake_klogd |= log_start - log_end;