serial: 8250: 8250_omap: Move locking out from __dma_rx_do_complete()

Caller functions of __dma_rx_do_complete() already hold rx_dma_lock.
Therefore move locking out of the function to avoid need to release and
reacquire lock.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200319110344.21348-4-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index bf1f2bba1d4175af2f5e7c4a819266ef107127dd..b4c246d5fadf9655a19d9ff35f9df4131a50311e 100644 (file)
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -736,22 +736,19 @@ static void omap_8250_unthrottle(struct uart_port *port)
 #ifdef CONFIG_SERIAL_8250_DMA
 static int omap_8250_rx_dma(struct uart_8250_port *p);
 
+/* Must be called while priv->rx_dma_lock is held */
 static void __dma_rx_do_complete(struct uart_8250_port *p)
 {
-       struct omap8250_priv    *priv = p->port.private_data;
        struct uart_8250_dma    *dma = p->dma;
        struct tty_port         *tty_port = &p->port.state->port;
        struct dma_chan         *rxchan = dma->rxchan;
        dma_cookie_t            cookie;
        struct dma_tx_state     state;
        int                     count;
-       unsigned long           flags;
        int                     ret;
 
-       spin_lock_irqsave(&priv->rx_dma_lock, flags);
-
        if (!dma->rx_running)
-               goto unlock;
+               goto out;
 
        cookie = dma->rx_cookie;
        dma->rx_running = 0;
@@ -777,13 +774,12 @@ static void __dma_rx_do_complete(struct uart_8250_port *p)
                }
        }
        if (!count)
-               goto unlock;
+               goto out;
        ret = tty_insert_flip_string(tty_port, dma->rx_buf, count);
 
        p->port.icount.rx += ret;
        p->port.icount.buf_overrun += count - ret;
-unlock:
-       spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
+out:
 
        tty_flip_buffer_push(tty_port);
 }
@@ -836,9 +832,8 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
                if (WARN_ON_ONCE(ret))
                        priv->rx_dma_broken = true;
        }
-       spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
-
        __dma_rx_do_complete(p);
+       spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
 }
 
 static int omap_8250_rx_dma(struct uart_8250_port *p)