The ACM_READY() macro doesn't seem to do anything useful, and it may
prevent tty_wait_until_sent() from working properly when called from
close.
Previously, acm_tty_chars_in_buffer() returned 0 whenever
acm->port.count was 0. This means close() could return before all the
data has actually been written.
Signed-off-by: Havard Skinnemoen <hskinnemoen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
 
 static DEFINE_MUTEX(acm_table_lock);
 
-#define ACM_READY(acm) (acm && acm->dev && acm->port.count)
-
 /*
  * acm_table accessors
  */
                goto exit;
        }
 
-       if (!ACM_READY(acm))
-               goto exit;
-
        usb_mark_last_busy(acm->dev);
 
        data = (unsigned char *)(dr + 1);
        spin_lock_irqsave(&acm->write_lock, flags);
        acm_write_done(acm, wb);
        spin_unlock_irqrestore(&acm->write_lock, flags);
-       if (ACM_READY(acm))
-               schedule_work(&acm->work);
+       schedule_work(&acm->work);
 }
 
 static void acm_softint(struct work_struct *work)
 
        dev_vdbg(&acm->data->dev, "%s\n", __func__);
 
-       if (!ACM_READY(acm))
-               return;
        tty = tty_port_tty_get(&acm->port);
        if (!tty)
                return;