USB: serial: option: add WeTelecom WM-D200

[pandora-kernel.git] / drivers / tty / tty_buffer.c

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 6c9b7cd..a846618 100644 (file)
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -114,11 +114,14 @@ static void __tty_buffer_flush(struct tty_struct *tty)
 {
        struct tty_buffer *thead;
 
-       while ((thead = tty->buf.head) != NULL) {
-               tty->buf.head = thead->next;
-               tty_buffer_free(tty, thead);
+       if (tty->buf.head == NULL)
+               return;
+       while ((thead = tty->buf.head->next) != NULL) {
+               tty_buffer_free(tty, tty->buf.head);
+               tty->buf.head = thead;
        }
-       tty->buf.tail = NULL;
+       WARN_ON(tty->buf.head != tty->buf.tail);
+       tty->buf.head->read = tty->buf.head->commit;
 }
 
 /**
@@ -439,10 +442,12 @@ static void flush_to_ldisc(struct work_struct *work)
                        char_buf = head->char_buf_ptr + head->read;
                        flag_buf = head->flag_buf_ptr + head->read;
                        head->read += count;
-                       spin_unlock_irqrestore(&tty->buf.lock, flags);
-                       disc->ops->receive_buf(tty, char_buf,
+                       if (disc->ops->receive_buf) {
+                               spin_unlock_irqrestore(&tty->buf.lock, flags);
+                               disc->ops->receive_buf(tty, char_buf,
                                                        flag_buf, count);
-                       spin_lock_irqsave(&tty->buf.lock, flags);
+                               spin_lock_irqsave(&tty->buf.lock, flags);
+                       }
                }
                clear_bit(TTY_FLUSHING, &tty->flags);
        }