From mboxrd@z Thu Jan 1 00:00:00 1970 From: sonic zhang Subject: [PATCH] [bfin-sport-uart] The waiting loop to stop SPORT TX from TX interrupt is too long Date: Mon, 21 Sep 2009 19:02:53 +0800 Message-ID: <1253530973.22138.16.camel@eight.analog.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from nwd2mail10.analog.com ([137.71.25.55]:32786 "EHLO nwd2mail10.analog.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751779AbZIULCH (ORCPT ); Mon, 21 Sep 2009 07:02:07 -0400 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Alan Cox , Linux Kernel , Linux Serial 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 --- 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