[RFC] get rid of CONFIG_DISABLE_CONSOLE_SUSPEND

[Pavel Machek <pavel@ucw.cz>]

Hi!

What about this? (Only compile tested, but looks pretty obvious to
me). Something like this should get us rid of ugly option, and still
solve debugging problems... Hmmm?
								Pavel

Kill CONFIG_DISABLE_CONSOLE_SUSPEND; it should not be configurable at
all, instead, we should automatically keep console alive when
possible.

Signed-off-by: Pavel Machek <pavel@suse.cz>

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 62051f8..8267ff8 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -144,7 +144,7 @@ static unsigned int lp_count = 0;
 static struct class *lp_class;
 
 #ifdef CONFIG_LP_CONSOLE
-static struct parport *console_registered; // initially NULL
+static struct parport *console_registered;
 #endif /* CONFIG_LP_CONSOLE */
 
 #undef LP_DEBUG
@@ -749,8 +749,8 @@ #endif /* console on line printer */
 /* --- initialisation code ------------------------------------- */
 
 static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
-static char *parport[LP_NO] = { NULL,  };
-static int reset = 0;
+static char *parport[LP_NO];
+static int reset;
 
 module_param_array(parport, charp, NULL, 0);
 module_param(reset, bool, 0);
@@ -758,10 +758,10 @@ module_param(reset, bool, 0);
 #ifndef MODULE
 static int __init lp_setup (char *str)
 {
-	static int parport_ptr; // initially zero
+	static int parport_ptr;
 	int x;
 
-	if (get_option (&str, &x)) {
+	if (get_option(&str, &x)) {
 		if (x == 0) {
 			/* disable driver on "lp=" or "lp=0" */
 			parport_nr[0] = LP_PARPORT_OFF;
@@ -808,7 +808,7 @@ static int lp_register(int nr, struct pa
 #ifdef CONFIG_LP_CONSOLE
 	if (!nr) {
 		if (port->modes & PARPORT_MODE_SAFEININT) {
-			register_console (&lpcons);
+			register_console(&lpcons);
 			console_registered = port;
 			printk (KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
 		} else
@@ -824,8 +824,7 @@ static void lp_attach (struct parport *p
 {
 	unsigned int i;
 
-	switch (parport_nr[0])
-	{
+	switch (parport_nr[0]) {
 	case LP_PARPORT_UNSPEC:
 	case LP_PARPORT_AUTO:
 		if (parport_nr[0] == LP_PARPORT_AUTO &&
@@ -856,7 +855,7 @@ static void lp_detach (struct parport *p
 	/* Write this some day. */
 #ifdef CONFIG_LP_CONSOLE
 	if (console_registered == port) {
-		unregister_console (&lpcons);
+		unregister_console(&lpcons);
 		console_registered = NULL;
 	}
 #endif /* CONFIG_LP_CONSOLE */
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 69233f6..7f7c2ce 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -75,7 +75,7 @@ static void write_msg(struct console *co
 
 	local_irq_save(flags);
 
-	for(left = len; left; ) {
+	for (left = len; left; ) {
 		frag = min(left, MAX_PRINT_CHUNK);
 		netpoll_send_udp(&np, msg, frag);
 		msg += frag;
@@ -103,10 +103,10 @@ static int init_netconsole(void)
 {
 	int err;
 
-	if(strlen(config))
+	if (strlen(config))
 		option_setup(config);
 
-	if(!configured) {
+	if (!configured) {
 		printk("netconsole: not configured, aborting\n");
 		return 0;
 	}
@@ -115,6 +115,7 @@ static int init_netconsole(void)
 	if (err)
 		return err;
 
+	disable_console_on_suspend++;
 	register_console(&netconsole);
 	printk(KERN_INFO "netconsole: network logging started\n");
 	return 0;
@@ -123,6 +124,7 @@ static int init_netconsole(void)
 static void cleanup_netconsole(void)
 {
 	unregister_console(&netconsole);
+	disable_console_on_suspend--;
 	netpoll_cleanup(&np);
 }
 
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 326020f..b2331a5 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1934,12 +1934,10 @@ int uart_suspend_port(struct uart_driver
 
 	mutex_lock(&state->mutex);
 
-#ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
 	if (uart_console(port)) {
 		mutex_unlock(&state->mutex);
 		return 0;
 	}
-#endif
 
 	if (state->info && state->info->flags & UIF_INITIALIZED) {
 		const struct uart_ops *ops = port->ops;
@@ -1982,12 +1980,10 @@ int uart_resume_port(struct uart_driver 
 
 	mutex_lock(&state->mutex);
 
-#ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
 	if (uart_console(port)) {
 		mutex_unlock(&state->mutex);
 		return 0;
 	}
-#endif
 
 	uart_change_pm(state, 0);
 
diff --git a/include/linux/console.h b/include/linux/console.h
index 62ef6e1..3cb477e 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -120,14 +120,11 @@ extern void console_stop(struct console 
 extern void console_start(struct console *);
 extern int is_console_locked(void);
 
-#ifndef CONFIG_DISABLE_CONSOLE_SUSPEND
+extern int disable_console_on_suspend;
+
 /* Suspend and resume console messages over PM events */
 extern void suspend_console(void);
 extern void resume_console(void);
-#else
-static inline void suspend_console(void) {}
-static inline void resume_console(void) {}
-#endif /* CONFIG_DISABLE_CONSOLE_SUSPEND */
 
 int mda_console_init(void);
 void prom_con_init(void);
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 7564c38..59f103b 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -37,17 +37,6 @@ config PM_DEBUG
 	code. This is helpful when debugging and reporting various PM bugs, 
 	like suspend support.
 
-config DISABLE_CONSOLE_SUSPEND
-	bool "Keep console(s) enabled during suspend/resume (DANGEROUS)"
-	depends on PM && PM_DEBUG
-	default n
-	---help---
-	This option turns off the console suspend mechanism that prevents
-	debug messages from reaching the console during the suspend/resume
-	operations.  This may be helpful when debugging device drivers'
-	suspend/resume routines, but may itself lead to problems, for example
-	if netconsole is used.
-
 config PM_TRACE
 	bool "Suspend/resume event tracing"
 	depends on PM && PM_DEBUG && X86_32 && EXPERIMENTAL
@@ -57,8 +46,8 @@ config PM_TRACE
 	RTC across reboots, so that you can debug a machine that just hangs
 	during suspend (or more commonly, during resume).
 
-	To use this debugging feature you should attempt to suspend the machine,
-	then reboot it, then run
+	To use this debugging feature you should attempt to suspend the
+	machine, then reboot it, then run
 
 		dmesg -s 1000000 | grep 'hash matches'
 
diff --git a/kernel/printk.c b/kernel/printk.c
index 0bbdeac..c057023 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -726,7 +726,8 @@ int __init add_preferred_console(char *n
 	return 0;
 }
 
-#ifndef CONFIG_DISABLE_CONSOLE_SUSPEND
+int disable_console_on_suspend;
+
 /**
  * suspend_console - suspend the console subsystem
  *
@@ -734,17 +735,22 @@ #ifndef CONFIG_DISABLE_CONSOLE_SUSPEND
  */
 void suspend_console(void)
 {
-	printk("Suspending console(s)\n");
-	acquire_console_sem();
-	console_suspended = 1;
+	if (disable_console_on_suspend) {
+		printk("Suspending console(s)\n");
+		acquire_console_sem();
+		console_suspended = 1;
+	}
 }
 
 void resume_console(void)
 {
-	console_suspended = 0;
-	release_console_sem();
+	if (console_suspended) {
+		BUG_ON(!disable_console_on_suspend);
+		console_suspended = 0;
+		release_console_sem();
+	}
 }
-#endif /* CONFIG_DISABLE_CONSOLE_SUSPEND */
+
 
 /**
  * acquire_console_sem - lock the console system for exclusive use.


-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html