From c8eb8b4025175f967af0ba8e933f23aa9954dc35 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 25 Sep 2006 23:32:56 -0700 Subject: [PATCH] [PATCH] PM: make it possible to disable console suspending Change suspend_console() so that it waits for all consoles to flush the remaining messages and make it possible to switch the console suspending off with the help of a Kconfig option. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Cc: Stefan Seyfried Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/console.h | 5 +++++ kernel/power/Kconfig | 11 +++++++++++ kernel/printk.c | 3 +++ 3 files changed, 19 insertions(+) diff --git a/include/linux/console.h b/include/linux/console.h index 3bdf2155e56..76a1807726e 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -120,9 +120,14 @@ extern void console_stop(struct console *); extern void console_start(struct console *); extern int is_console_locked(void); +#ifndef CONFIG_DISABLE_CONSOLE_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 */ /* Some debug stub to catch some of the obvious races in the VT code */ #if 1 diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 619ecabf7c5..4b6e2f18e05 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -36,6 +36,17 @@ 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 diff --git a/kernel/printk.c b/kernel/printk.c index 1149365e989..771f5e861bc 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -721,6 +721,7 @@ int __init add_preferred_console(char *name, int idx, char *options) return 0; } +#ifndef CONFIG_DISABLE_CONSOLE_SUSPEND /** * suspend_console - suspend the console subsystem * @@ -728,6 +729,7 @@ int __init add_preferred_console(char *name, int idx, char *options) */ void suspend_console(void) { + printk("Suspending console(s)\n"); acquire_console_sem(); console_suspended = 1; } @@ -737,6 +739,7 @@ void resume_console(void) console_suspended = 0; release_console_sem(); } +#endif /* CONFIG_DISABLE_CONSOLE_SUSPEND */ /** * acquire_console_sem - lock the console system for exclusive use. -- 2.41.1