The waiting loop to stop SPORT TX from TX interrupt is too long. This may block SPORT RX interrupts and cause RX FIFO overflow. So, do stop sport TX only after the last char in TX FIFO is moved into the shift register. Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx> --- drivers/serial/bfin_sport_uart.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c index c108b1a..fb9f7cd 100644 --- a/drivers/serial/bfin_sport_uart.c +++ b/drivers/serial/bfin_sport_uart.c @@ -303,7 +303,13 @@ static void sport_uart_tx_chars(struct sport_uart_port *up) } if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { - sport_stop_tx(&up->port); + /* The waiting loop to stop SPORT TX from TX interrupt is + * too long. This may block SPORT RX interrupts and cause + * RX FIFO overflow. So, do stop sport TX only after the last + * char in TX FIFO is moved into the shift register. + */ + if (SPORT_GET_STAT(up) & TXHRE) + sport_stop_tx(&up->port); return; } -- 1.6.0 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html