Pull ec into release branch

[pandora-kernel.git] / drivers / char / vt_ioctl.c

diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index 3a5d301..c9f2dd6 100644 (file)
--- 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)
@@ -1039,10 +1039,22 @@ int vt_waitactive(int vt)
 
        add_wait_queue(&vt_activate_queue, &wait);
        for (;;) {
-               set_current_state(TASK_INTERRUPTIBLE);
                retval = 0;
-               if (vt == fg_console)
+
+               /*
+                * Synchronize with redraw_screen(). By acquiring the console
+                * semaphore we make sure that the console switch is completed
+                * before we return. If we didn't wait for the semaphore, we
+                * could return at a point where fg_console has already been
+                * updated, but the console switch hasn't been completed.
+                */
+               acquire_console_sem();
+               set_current_state(TASK_INTERRUPTIBLE);
+               if (vt == fg_console) {
+                       release_console_sem();
                        break;
+               }
+               release_console_sem();
                retval = -EINTR;
                if (signal_pending(current))
                        break;