serial: 8250: 8250_omap: Terminate DMA before pushing data on RX timeout

Terminate and flush DMA internal buffers, before pushing RX data to
higher layer. Otherwise, this will lead to data corruption, as driver
would end up pushing stale buffer data to higher layer while actual data
is still stuck inside DMA hardware and has yet not arrived at the
memory.
While at that, replace deprecated dmaengine_terminate_all() with
dmaengine_terminate_async().

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200319110344.21348-2-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 1395ff7b03e76938dba02fb9aa659e69e2a6fd1b..c13b48ad7cdbc0ea3920991a6353775ca08a026a 100644 (file)
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -755,7 +755,10 @@ static void __dma_rx_do_complete(struct uart_8250_port *p)
        dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
 
        count = dma->rx_size - state.residue;
-
+       if (count < dma->rx_size)
+               dmaengine_terminate_async(dma->rxchan);
+       if (!count)
+               goto unlock;
        ret = tty_insert_flip_string(tty_port, dma->rx_buf, count);
 
        p->port.icount.rx += ret;
@@ -817,7 +820,6 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
        spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
 
        __dma_rx_do_complete(p);
-       dmaengine_terminate_all(dma->rxchan);
 }
 
 static int omap_8250_rx_dma(struct uart_8250_port *p)