diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index 39c61a7..cc7acf8 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -1233,7 +1233,7 @@
                             }
                              info->idle_stats.recv_idle = jiffies;
                         }
-                        schedule_delayed_work(&tty->buf.work, 1);
+			tty_schedule_flip(tty);
                     }
                     /* end of service */
                     cy_writeb(base_addr+(CyRIR<<index), (save_xir & 0x3f));
@@ -1606,7 +1606,7 @@
 	    }
 #endif
 	    info->idle_stats.recv_idle = jiffies;
-	    schedule_delayed_work(&tty->buf.work, 1);
+	    tty_schedule_flip(tty);
 	}
 	/* Update rx_get */
 	cy_writel(&buf_ctrl->rx_get, new_rx_get);
@@ -1809,7 +1809,7 @@
 	if(delta_count)
 	    cy_sched_event(info, Cy_EVENT_DELTA_WAKEUP);
 	if(special_count)
-	    schedule_delayed_work(&tty->buf.work, 1);
+	    tty_schedule_flip(tty);
     }
 }
 
diff --git a/drivers/char/esp.c b/drivers/char/esp.c
index 3f3ac03..57539d8 100644
--- a/drivers/char/esp.c
+++ b/drivers/char/esp.c
@@ -359,7 +359,7 @@
 		}
 	}
 
-	schedule_delayed_work(&tty->buf.work, 1);
+	tty_schedule_flip(tty);
 
 	info->stat_flags &= ~ESP_STAT_RX_TIMEOUT;
 	release_pio_buffer(pio_buf);
@@ -426,7 +426,7 @@
 			}
 			tty_insert_flip_char(tty, dma_buffer[num_bytes - 1], statflag);
 		}
-		schedule_delayed_work(&tty->buf.work, 1);
+		tty_schedule_flip(tty);
 	}
 
 	if (dma_bytes != num_bytes) {
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index eb8b5be..076e07c 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -253,6 +253,7 @@
 
 static void tty_buffer_init(struct tty_struct *tty)
 {
+	spin_lock_init(&tty->buf.lock);
 	tty->buf.head = NULL;
 	tty->buf.tail = NULL;
 	tty->buf.free = NULL;
@@ -266,6 +267,7 @@
 	p->used = 0;
 	p->size = size;
 	p->next = NULL;
+	p->active = 0;
 	p->char_buf_ptr = (char *)(p->data);
 	p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
 /* 	printk("Flip create %p\n", p); */
@@ -312,25 +314,36 @@
 
 int tty_buffer_request_room(struct tty_struct *tty, size_t size)
 {
-	struct tty_buffer *b = tty->buf.tail, *n;
-	int left = 0;
+	struct tty_buffer *b, *n;
+	int left;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->buf.lock, flags);
 
 	/* OPTIMISATION: We could keep a per tty "zero" sized buffer to
 	   remove this conditional if its worth it. This would be invisible
 	   to the callers */
-	if(b != NULL)
+	if ((b = tty->buf.tail) != NULL) {
 		left = b->size - b->used;
-	if(left >= size)
-		return size;
-	/* This is the slow path - looking for new buffers to use */
-	n = tty_buffer_find(tty, size);
-	if(n == NULL)
-		return left;
-	if(b != NULL)
-		b->next = n;
-	else
-		tty->buf.head = n;
-	tty->buf.tail = n;
+		b->active = 1;
+	} else
+		left = 0;
+
+	if (left < size) {
+		/* This is the slow path - looking for new buffers to use */
+		if ((n = tty_buffer_find(tty, size)) != NULL) {
+			if (b != NULL) {
+				b->next = n;
+				b->active = 0;
+			} else
+				tty->buf.head = n;
+			tty->buf.tail = n;
+			n->active = 1;
+		} else
+			size = left;
+	}
+
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
 	return size;
 }
 
@@ -396,10 +409,12 @@
 int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size)
 {
 	int space = tty_buffer_request_room(tty, size);
-	struct tty_buffer *tb = tty->buf.tail;
-	*chars = tb->char_buf_ptr + tb->used;
-	memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
-	tb->used += space;
+	if (likely(space)) {
+		struct tty_buffer *tb = tty->buf.tail;
+		*chars = tb->char_buf_ptr + tb->used;
+		memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+		tb->used += space;
+	}
 	return space;
 }
 
@@ -416,10 +431,12 @@
 int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size)
 {
 	int space = tty_buffer_request_room(tty, size);
-	struct tty_buffer *tb = tty->buf.tail;
-	*chars = tb->char_buf_ptr + tb->used;
-	*flags = tb->flag_buf_ptr + tb->used;
-	tb->used += space;
+	if (likely(space)) {
+		struct tty_buffer *tb = tty->buf.tail;
+		*chars = tb->char_buf_ptr + tb->used;
+		*flags = tb->flag_buf_ptr + tb->used;
+		tb->used += space;
+	}
 	return space;
 }
 
@@ -2747,20 +2764,20 @@
 		schedule_delayed_work(&tty->buf.work, 1);
 		goto out;
 	}
-	spin_lock_irqsave(&tty->read_lock, flags);
-	while((tbuf = tty->buf.head) != NULL) {
+	spin_lock_irqsave(&tty->buf.lock, flags);
+	while((tbuf = tty->buf.head) != NULL && !tbuf->active) {
 		tty->buf.head = tbuf->next;
 		if (tty->buf.head == NULL)
 			tty->buf.tail = NULL;
-		spin_unlock_irqrestore(&tty->read_lock, flags);
+		spin_unlock_irqrestore(&tty->buf.lock, flags);
 		/* printk("Process buffer %p for %d\n", tbuf, tbuf->used); */
 		disc->receive_buf(tty, tbuf->char_buf_ptr,
 				       tbuf->flag_buf_ptr,
 				       tbuf->used);
-		spin_lock_irqsave(&tty->read_lock, flags);
+		spin_lock_irqsave(&tty->buf.lock, flags);
 		tty_buffer_free(tty, tbuf);
 	}
-	spin_unlock_irqrestore(&tty->read_lock, flags);
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
 out:
 	tty_ldisc_deref(disc);
 }
@@ -2852,6 +2869,12 @@
 
 void tty_flip_buffer_push(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);
+
 	if (tty->low_latency)
 		flush_to_ldisc((void *) tty);
 	else