tty: flush flip buffer on ldisc input queue flush

[profile/ivi/kernel-adaptation-intel-automotive.git] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index bc84995..75d2a46 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -369,6 +369,29 @@ static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
 }
 
 /**
+ *     tty_buffer_flush                -       flush full tty buffers
+ *     @tty: tty to flush
+ *
+ *     flush all the buffers containing receive data
+ *
+ *     Locking: none
+ */
+
+static void tty_buffer_flush(struct tty_struct *tty)
+{
+       struct tty_buffer *thead;
+       unsigned long flags;
+
+       spin_lock_irqsave(&tty->buf.lock, flags);
+       while((thead = tty->buf.head) != NULL) {
+               tty->buf.head = thead->next;
+               tty_buffer_free(tty, thead);
+       }
+       tty->buf.tail = NULL;
+       spin_unlock_irqrestore(&tty->buf.lock, flags);
+}
+
+/**
  *     tty_buffer_find         -       find a free tty buffer
  *     @tty: tty owning the buffer
  *     @size: characters wanted
@@ -1248,6 +1271,7 @@ void tty_ldisc_flush(struct tty_struct *tty)
                        ld->flush_buffer(tty);
                tty_ldisc_deref(ld);
        }
+       tty_buffer_flush(tty);
 }
 
 EXPORT_SYMBOL_GPL(tty_ldisc_flush);
@@ -3350,6 +3374,15 @@ int tty_ioctl(struct inode * inode, struct file * file,
                case TIOCMBIC:
                case TIOCMBIS:
                        return tty_tiocmset(tty, file, cmd, p);
+               case TCFLSH:
+                       switch (arg) {
+                       case TCIFLUSH:
+                       case TCIOFLUSH:
+                               /* flush tty buffer and allow ldisc to process ioctl */
+                               tty_buffer_flush(tty);
+                               break;
+                       }
+                       break;
        }
        if (tty->driver->ioctl) {
                retval = (tty->driver->ioctl)(tty, file, cmd, arg);