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authorAndrew Johnson <ajohnson@intrinsyc.com>2007-03-16 13:38:24 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-16 19:25:05 -0700
commitb257bc051f06607beb3004d9a1c297085e728bec (patch)
tree2eeb60429d92b683e9593d2fcde2f22ae40a1bf4
parent1174cf730179d8f029b9e93cb9a4d5bfb08d1202 (diff)
downloadlwn-b257bc051f06607beb3004d9a1c297085e728bec.tar.gz
lwn-b257bc051f06607beb3004d9a1c297085e728bec.zip
[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 <ajohnson@intrinsyc.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: "Antonino A. Daplas" <adaplas@pol.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/char/vt.c20
-rw-r--r--drivers/char/vt_ioctl.c2
-rw-r--r--include/linux/kbd_kern.h2
-rw-r--r--include/linux/vt_kern.h1
-rw-r--r--kernel/power/console.c10
5 files changed, 31 insertions, 4 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index c3f8e383933b..0fefe2a28055 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 3a5d301e783b..1fa2da8f4fbe 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -34,7 +34,7 @@
#include <linux/kbd_diacr.h>
#include <linux/selection.h>
-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 06c58c423fe1..506ad20c18f8 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 37a1a41f5b65..e0db669998f3 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 623786d44159..89bcf4973ee5 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)) {