[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>

1 files changed, 9 insertions, 1 deletions

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)) {