serial: 8250_mid: Read RX buffer on RX DMA timeout for DNV

In DNV, when RX DMA is used and number of bytes received is less than
transfer size, only RX DMA timeout interrupt is sent. When this happens,
read the RX buffer.

Signed-off-by: Chuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
index b218ff528df756ae2718f04209e433dc133e17e2..339de9cd086612c60d17ef3c581b59df34a0022a 100644 (file)
--- a/drivers/tty/serial/8250/8250_mid.c
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -96,6 +96,7 @@ static int tng_setup(struct mid8250 *mid, struct uart_port *p)
 static int dnv_handle_irq(struct uart_port *p)
 {
        struct mid8250 *mid = p->private_data;
+       struct uart_8250_port *up = up_to_u8250p(p);
        unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
        u32 status;
        int ret = IRQ_NONE;
@@ -103,9 +104,10 @@ static int dnv_handle_irq(struct uart_port *p)
 
        if (fisr & BIT(2)) {
                err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
-               if (err > 0)
+               if (err > 0) {
+                       serial8250_rx_dma_flush(up);
                        ret |= IRQ_HANDLED;
-               else if (err == 0)
+               } else if (err == 0)
                        ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status);
        }
        if (fisr & BIT(1)) {