From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [RFC][PATCH] PM: Use suspend_console in swsusp and make it configureable Date: Tue, 15 Aug 2006 15:09:05 +0200 Message-ID: <200608151509.06087.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: 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: LKML Cc: Linux PM , Pavel Machek List-Id: linux-pm@vger.kernel.org Hi, The appended patch does the following: 1) Adds suspend_console() and resume_console() to the suspend-to-disk code paths so that people using netconsole are safe with swsusp. 2) Adds a Kconfig option allowing us to disable suspend_/resume_console() if need be. 3) Marks CONFIG_PM_TRACE as dangerous. Comments welcome. Greetings, Rafael Signed-off-by: Rafael J. Wysocki --- include/linux/console.h | 5 +++++ kernel/power/Kconfig | 13 ++++++++++++- kernel/power/disk.c | 8 ++++++++ kernel/power/user.c | 8 +++++++- kernel/printk.c | 2 ++ 5 files changed, 34 insertions(+), 2 deletions(-) Index: linux-2.6.18-rc4-mm1/kernel/power/disk.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/power/disk.c +++ linux-2.6.18-rc4-mm1/kernel/power/disk.c @@ -18,6 +18,7 @@ #include #include #include +#include #include = #include "power.h" @@ -119,8 +120,10 @@ int pm_suspend_disk(void) if (error) return error; = + suspend_console(); error =3D device_suspend(PMSG_FREEZE); if (error) { + resume_console(); printk("Some devices failed to suspend\n"); unprepare_processes(); return error; @@ -133,6 +136,7 @@ int pm_suspend_disk(void) = if (in_suspend) { device_resume(); + resume_console(); pr_debug("PM: writing image.\n"); error =3D swsusp_write(); if (!error) @@ -148,6 +152,7 @@ int pm_suspend_disk(void) swsusp_free(); Done: device_resume(); + resume_console(); unprepare_processes(); return error; } @@ -212,7 +217,9 @@ static int software_resume(void) = pr_debug("PM: Preparing devices for restore.\n"); = + suspend_console(); if ((error =3D device_suspend(PMSG_PRETHAW))) { + resume_console(); printk("Some devices failed to suspend\n"); swsusp_free(); goto Thaw; @@ -224,6 +231,7 @@ static int software_resume(void) swsusp_resume(); pr_debug("PM: Restore failed, recovering.n"); device_resume(); + resume_console(); Thaw: unprepare_processes(); Done: Index: linux-2.6.18-rc4-mm1/kernel/power/user.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/power/user.c +++ linux-2.6.18-rc4-mm1/kernel/power/user.c @@ -19,6 +19,7 @@ #include #include #include +#include #include = #include @@ -173,12 +174,14 @@ static int snapshot_ioctl(struct inode * /* Free memory before shutting down devices. */ error =3D swsusp_shrink_memory(); if (!error) { + suspend_console(); error =3D device_suspend(PMSG_FREEZE); if (!error) { in_suspend =3D 1; error =3D swsusp_suspend(); device_resume(); } + resume_console(); } up(&pm_sem); if (!error) @@ -196,11 +199,13 @@ static int snapshot_ioctl(struct inode * } down(&pm_sem); pm_prepare_console(); + suspend_console(); error =3D device_suspend(PMSG_PRETHAW); if (!error) { error =3D swsusp_resume(); device_resume(); } + resume_console(); pm_restore_console(); up(&pm_sem); break; @@ -289,6 +294,7 @@ static int snapshot_ioctl(struct inode * } = /* Put devices to sleep */ + suspend_console(); error =3D device_suspend(PMSG_SUSPEND); if (error) { printk(KERN_ERR "Failed to suspend some devices.\n"); @@ -299,7 +305,7 @@ static int snapshot_ioctl(struct inode * /* Wake up devices */ device_resume(); } - + resume_console(); if (pm_ops->finish) pm_ops->finish(PM_SUSPEND_MEM); = 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 +++ linux-2.6.18-rc4-mm1/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_PM_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_PM_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 +++ linux-2.6.18-rc4-mm1/kernel/power/Kconfig @@ -36,8 +36,19 @@ 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" + bool "Suspend/resume event tracing (DANGEROUS)" depends on PM && PM_DEBUG && X86_32 && EXPERIMENTAL default n ---help--- 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 +++ linux-2.6.18-rc4-mm1/kernel/printk.c @@ -702,6 +702,7 @@ int __init add_preferred_console(char *n return 0; } = +#ifndef CONFIG_PM_DISABLE_CONSOLE_SUSPEND /** * suspend_console - suspend the console subsystem * @@ -718,6 +719,7 @@ void resume_console(void) console_suspended =3D 0; release_console_sem(); } +#endif /* CONFIG_PM_DISABLE_CONSOLE_SUSPEND */ = /** * acquire_console_sem - lock the console system for exclusive use.