serial: sh-sci: fix a race of DMA submit_tx on transfer

[pandora-kernel.git] / drivers / tty / serial / sh-sci.c

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index aff9d61..829e51a 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1123,17 +1123,20 @@ static void sci_dma_tx_complete(void *arg)
        port->icount.tx += sg_dma_len(&s->sg_tx);
 
        async_tx_ack(s->desc_tx);
-       s->cookie_tx = -EINVAL;
        s->desc_tx = NULL;
 
        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                uart_write_wakeup(port);
 
        if (!uart_circ_empty(xmit)) {
+               s->cookie_tx = 0;
                schedule_work(&s->work_tx);
-       } else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
-               u16 ctrl = sci_in(port, SCSCR);
-               sci_out(port, SCSCR, ctrl & ~SCSCR_TIE);
+       } else {
+               s->cookie_tx = -EINVAL;
+               if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+                       u16 ctrl = sci_in(port, SCSCR);
+                       sci_out(port, SCSCR, ctrl & ~SCSCR_TIE);
+               }
        }
 
        spin_unlock_irqrestore(&port->lock, flags);
@@ -1395,8 +1398,10 @@ static void sci_start_tx(struct uart_port *port)
        }
 
        if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
-           s->cookie_tx < 0)
+           s->cookie_tx < 0) {
+               s->cookie_tx = 0;
                schedule_work(&s->work_tx);
+       }
 #endif
 
        if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {