3 files changed, 13 insertions, 1 deletions

diff --git a/include/linux/kbd_kern.h b/include/linux/kbd_kern.h
index 45f625d7d0b2..3aed37314ab8 100644
--- a/include/linux/kbd_kern.h
+++ b/include/linux/kbd_kern.h
@@ -151,6 +151,11 @@ extern unsigned int keymap_count;
 
 static inline void con_schedule_flip(struct tty_struct *t)
 {
+        unsigned long flags;
+        spin_lock_irqsave(&t->buf.lock, flags);
+        if (t->buf.tail != NULL)
+                t->buf.tail->active = 0;
+        spin_unlock_irqrestore(&t->buf.lock, flags);
         schedule_work(&t->buf.work);
 }
 
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 3787102e4b12..a7bd3b4558d2 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -57,6 +57,7 @@ struct tty_buffer {
         unsigned char *flag_buf_ptr;
         int used;
         int size;
+        int active;
         /* Data points here */
         unsigned long data[0];
 };
@@ -64,6 +65,7 @@ struct tty_buffer {
 struct tty_bufhead {
         struct work_struct              work;
         struct semaphore pty_sem;
+        spinlock_t lock;
         struct tty_buffer *head;        /* Queue head */
         struct tty_buffer *tail;        /* Active buffer */
         struct tty_buffer *free;        /* Free queue head */
diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h
index be1400e82482..82961eb19888 100644
--- a/include/linux/tty_flip.h
+++ b/include/linux/tty_flip.h
@@ -17,7 +17,7 @@ _INLINE_ int tty_insert_flip_char(struct tty_struct *tty,
                                    unsigned char ch, char flag)
 {
         struct tty_buffer *tb = tty->buf.tail;
-        if (tb && tb->used < tb->size) {
+        if (tb && tb->active && tb->used < tb->size) {
                 tb->flag_buf_ptr[tb->used] = flag;
                 tb->char_buf_ptr[tb->used++] = ch;
                 return 1;
@@ -27,6 +27,11 @@ _INLINE_ int tty_insert_flip_char(struct tty_struct *tty,
 
 _INLINE_ void tty_schedule_flip(struct tty_struct *tty)
 {
+        unsigned long flags;
+        spin_lock_irqsave(&tty->buf.lock, flags);
+        if (tty->buf.tail != NULL)
+                tty->buf.tail->active = 0;
+        spin_unlock_irqrestore(&tty->buf.lock, flags);
         schedule_delayed_work(&tty->buf.work, 1);
 }