From b257bc051f06607beb3004d9a1c297085e728bec Mon Sep 17 00:00:00 2001 From: Andrew Johnson Date: Fri, 16 Mar 2007 13:38:24 -0800 Subject: [PATCH] [PATCH] swsusp: fix suspend when console is in VT_AUTO+KD_GRAPHICS mode When the console is in VT_AUTO+KD_GRAPHICS mode, switching to the SUSPEND_CONSOLE fails, resulting in vt_waitactive() waiting indefinitely or until the task is interrupted. This patch tests if a console switch can occur in set_console() and returns early if a console switch is not possible. [akpm@linux-foundation.org: cleanup] Signed-off-by: Andrew Johnson Acked-by: Pavel Machek Cc: "Antonino A. Daplas" Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/vt.c | 20 +++++++++++++++++++- drivers/char/vt_ioctl.c | 2 +- include/linux/kbd_kern.h | 2 +- include/linux/vt_kern.h | 1 + kernel/power/console.c | 10 +++++++++- 5 files changed, 31 insertions(+), 4 deletions(-) diff --git a/drivers/char/vt.c b/drivers/char/vt.c index c3f8e38393..0fefe2a280 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -2185,10 +2185,28 @@ static void console_callback(struct work_struct *ignored) release_console_sem(); } -void set_console(int nr) +int set_console(int nr) { + struct vc_data *vc = vc_cons[fg_console].d; + + if (!vc_cons_allocated(nr) || vt_dont_switch || + (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) { + + /* + * Console switch will fail in console_callback() or + * change_console() so there is no point scheduling + * the callback + * + * Existing set_console() users don't check the return + * value so this shouldn't break anything + */ + return -EINVAL; + } + want_console = nr; schedule_console_callback(); + + return 0; } struct tty_driver *console_driver; diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c index 3a5d301e78..1fa2da8f4f 100644 --- a/drivers/char/vt_ioctl.c +++ b/drivers/char/vt_ioctl.c @@ -34,7 +34,7 @@ #include #include -static char vt_dont_switch; +char vt_dont_switch; extern struct tty_driver *console_driver; #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count) diff --git a/include/linux/kbd_kern.h b/include/linux/kbd_kern.h index 06c58c423f..506ad20c18 100644 --- a/include/linux/kbd_kern.h +++ b/include/linux/kbd_kern.h @@ -75,7 +75,7 @@ extern int do_poke_blanked_console; extern void (*kbd_ledfunc)(unsigned int led); -extern void set_console(int nr); +extern int set_console(int nr); extern void schedule_console_callback(void); static inline void set_leds(void) diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h index 37a1a41f5b..e0db669998 100644 --- a/include/linux/vt_kern.h +++ b/include/linux/vt_kern.h @@ -83,6 +83,7 @@ void reset_vc(struct vc_data *vc); #define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE) extern char con_buf[CON_BUF_SIZE]; extern struct semaphore con_buf_sem; +extern char vt_dont_switch; struct vt_spawn_console { spinlock_t lock; diff --git a/kernel/power/console.c b/kernel/power/console.c index 623786d441..89bcf4973e 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -27,7 +27,15 @@ int pm_prepare_console(void) return 1; } - set_console(SUSPEND_CONSOLE); + if (set_console(SUSPEND_CONSOLE)) { + /* + * We're unable to switch to the SUSPEND_CONSOLE. + * Let the calling function know so it can decide + * what to do. + */ + release_console_sem(); + return 1; + } release_console_sem(); if (vt_waitactive(SUSPEND_CONSOLE)) { -- 2.39.5