UPSTREAM: drm/edid: Extract SADs properly from multiple audio data blocks
[firefly-linux-kernel-4.4.55.git] / drivers / tty / tty_buffer.c
index 9a479e61791a2a80cd0ae3fd5c93c6d0873d6998..fb31eecb708dfa10bc5e308384cc02ff8fcdd025 100644 (file)
 
 #define TTY_BUFFER_PAGE        (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
 
-/*
- * If all tty flip buffers have been processed by flush_to_ldisc() or
- * dropped by tty_buffer_flush(), check if the linked pty has been closed.
- * If so, wake the reader/poll to process
- */
-static inline void check_other_closed(struct tty_struct *tty)
-{
-       unsigned long flags, old;
-
-       /* transition from TTY_OTHER_CLOSED => TTY_OTHER_DONE must be atomic */
-       for (flags = ACCESS_ONCE(tty->flags);
-            test_bit(TTY_OTHER_CLOSED, &flags);
-            ) {
-               old = flags;
-               __set_bit(TTY_OTHER_DONE, &flags);
-               flags = cmpxchg(&tty->flags, old, flags);
-               if (old == flags) {
-                       wake_up_interruptible(&tty->read_wait);
-                       break;
-               }
-       }
-}
-
 /**
  *     tty_buffer_lock_exclusive       -       gain exclusive access to buffer
  *     tty_buffer_unlock_exclusive     -       release exclusive access
@@ -254,8 +231,6 @@ void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
        if (ld && ld->ops->flush_buffer)
                ld->ops->flush_buffer(tty);
 
-       check_other_closed(tty);
-
        atomic_dec(&buf->priority);
        mutex_unlock(&buf->lock);
 }
@@ -450,7 +425,7 @@ receive_buf(struct tty_struct *tty, struct tty_buffer *head, int count)
                count = disc->ops->receive_buf2(tty, p, f, count);
        else {
                count = min_t(int, count, tty->receive_room);
-               if (count)
+               if (count && disc->ops->receive_buf)
                        disc->ops->receive_buf(tty, p, f, count);
        }
        return count;
@@ -505,10 +480,8 @@ static void flush_to_ldisc(struct work_struct *work)
                 */
                count = smp_load_acquire(&head->commit) - head->read;
                if (!count) {
-                       if (next == NULL) {
-                               check_other_closed(tty);
+                       if (next == NULL)
                                break;
-                       }
                        buf->head = next;
                        tty_buffer_free(port, head);
                        continue;
@@ -597,3 +570,8 @@ bool tty_buffer_cancel_work(struct tty_port *port)
 {
        return cancel_work_sync(&port->buf.work);
 }
+
+void tty_buffer_flush_work(struct tty_port *port)
+{
+       flush_work(&port->buf.work);
+}