Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux
[linux-2.6-block.git] / drivers / tty / serial / pmac_zilog.c
index 01e180bc6b5d1c27b7120fa5296683c4b865138e..abbfedb84901731793aeddef5a98910c72520b42 100644 (file)
@@ -653,6 +653,8 @@ static void pmz_start_tx(struct uart_port *port)
        } else {
                struct circ_buf *xmit = &port->state->xmit;
 
+               if (uart_circ_empty(xmit))
+                       goto out;
                write_zsdata(uap, xmit->buf[xmit->tail]);
                zssync(uap);
                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -661,6 +663,7 @@ static void pmz_start_tx(struct uart_port *port)
                if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                        uart_write_wakeup(&uap->port);
        }
+ out:
        pmz_debug("pmz: start_tx() done.\n");
 }