diff options
| -rw-r--r-- | drivers/tty/serial/imx.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index ab958a59cae9..d61b89e4a96e 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -946,8 +946,21 @@ static void dma_rx_callback(void *data) tty_flip_buffer_push(port); start_rx_dma(sport); - } else + } else if (readl(sport->port.membase + USR2) & USR2_RDR) { + /* + * start rx_dma directly once data in RXFIFO, more efficient + * than before: + * 1. call imx_rx_dma_done to stop dma if no data received + * 2. wait next RDR interrupt to start dma transfer. + */ + start_rx_dma(sport); + } else { + /* + * stop dma to prevent too many IDLE event trigged if no data + * in RXFIFO + */ imx_rx_dma_done(sport); + } } static int start_rx_dma(struct imx_port *sport) |