From 3f3a978b9f4a513610b32f16670914006a61067f Mon Sep 17 00:00:00 2001 From: Sonic Zhang Date: Tue, 9 Mar 2010 12:25:29 -0500 Subject: [PATCH] serial: bfin_sport_uart: shorten the SPORT TX waiting loop The waiting loop to stop SPORT TX from TX interrupt is too long. This may block the SPORT RX interrupts and cause the RX FIFO to 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 Signed-off-by: Mike Frysinger Signed-off-by: Greg Kroah-Hartman --- drivers/serial/bfin_sport_uart.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c index c88f8ad3ff82..6991c3605f9c 100644 --- a/drivers/serial/bfin_sport_uart.c +++ b/drivers/serial/bfin_sport_uart.c @@ -271,7 +271,13 @@ 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; }