serial: sh-sci: Redirect port interrupts to CPU _only_ when DMA stops

Since the DMA engine is not stopped everytime rx_timer_fn is called, the
interrupts have to be redirected back to CPU only when incomplete DMA
transaction is handled

Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 36a1111..5dcd8b3 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1285,12 +1285,6 @@ static void rx_timer_fn(unsigned long arg)
        spin_lock_irqsave(&port->lock, flags);
 
        dev_dbg(port->dev, "DMA Rx timed out\n");
-       scr = serial_port_in(port, SCSCR);
-       if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
-               scr &= ~SCSCR_RDRQE;
-               enable_irq(s->irqs[SCIx_RXI_IRQ]);
-       }
-       serial_port_out(port, SCSCR, scr | SCSCR_RIE);
 
        active = sci_dma_rx_find_active(s);
        if (active < 0) {
@@ -1315,10 +1309,18 @@ static void rx_timer_fn(unsigned long arg)
                        tty_flip_buffer_push(&port->state->port);
        }
 
-       spin_unlock_irqrestore(&port->lock, flags);
-
        if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
                sci_submit_rx(s);
+
+       /* Direct new serial port interrupts back to CPU */
+       scr = serial_port_in(port, SCSCR);
+       if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+               scr &= ~SCSCR_RDRQE;
+               enable_irq(s->irqs[SCIx_RXI_IRQ]);
+       }
+       serial_port_out(port, SCSCR, scr | SCSCR_RIE);
+
+       spin_unlock_irqrestore(&port->lock, flags);
 }
 
 static void sci_request_dma(struct uart_port *port)