From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [RFC][PATCH 2/3] PM: Make console suspending configureable Date: Wed, 16 Aug 2006 13:09:34 +0200 Message-ID: <200608161309.34370.rjw@sisk.pl> References: <200608151509.06087.rjw@sisk.pl> <20060816104143.GC9497@elf.ucw.cz> <200608161304.51758.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200608161304.51758.rjw@sisk.pl> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: Pavel Machek Cc: Linux PM , LKML List-Id: linux-pm@vger.kernel.org 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 --- include/linux/console.h | 5 +++++ kernel/power/Kconfig | 11 +++++++++++ kernel/printk.c | 8 ++++++++ 3 files changed, 24 insertions(+) Index: linux-2.6.18-rc4-mm1/include/linux/console.h =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- linux-2.6.18-rc4-mm1.orig/include/linux/console.h 2006-08-16 11:59:56.0= 00000000 +0200 +++ linux-2.6.18-rc4-mm1/include/linux/console.h 2006-08-16 12:00:01.000000= 000 +0200 @@ -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 Index: linux-2.6.18-rc4-mm1/kernel/power/Kconfig =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- linux-2.6.18-rc4-mm1.orig/kernel/power/Kconfig 2006-08-16 11:59:56.0000= 00000 +0200 +++ linux-2.6.18-rc4-mm1/kernel/power/Kconfig 2006-08-16 12:01:26.000000000= +0200 @@ -36,6 +36,17 @@ config PM_DEBUG code. This is helpful when debugging and reporting various PM bugs, = like suspend support. = +config PM_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 Index: linux-2.6.18-rc4-mm1/kernel/printk.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- linux-2.6.18-rc4-mm1.orig/kernel/printk.c 2006-08-16 11:59:56.000000000= +0200 +++ linux-2.6.18-rc4-mm1/kernel/printk.c 2006-08-16 12:08:59.000000000 +0200 @@ -702,6 +702,7 @@ int __init add_preferred_console(char *n return 0; } = +#ifndef CONFIG_DISABLE_CONSOLE_SUSPEND /** * suspend_console - suspend the console subsystem * @@ -709,8 +710,14 @@ int __init add_preferred_console(char *n */ void suspend_console(void) { + printk("Suspending console(s)\n"); acquire_console_sem(); console_suspended =3D 1; + /* This is needed so that all of the messages that have already been + * written to all consoles can be actually transmitted (eg. over a + * network) before we try to suspend the consoles' devices. + */ + ssleep(2); } = void resume_console(void) @@ -718,6 +725,7 @@ void resume_console(void) console_suspended =3D 0; release_console_sem(); } +#endif /* CONFIG_DISABLE_CONSOLE_SUSPEND */ = /** * acquire_console_sem - lock the console system for exclusive use.