Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753104AbZIULCK (ORCPT ); Mon, 21 Sep 2009 07:02:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752618AbZIULCI (ORCPT ); Mon, 21 Sep 2009 07:02:08 -0400 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 X-IronPort-AV: E=Sophos;i="4.44,424,1249272000"; d="scan'208";a="4697764" Subject: [PATCH] [bfin-sport-uart] The waiting loop to stop SPORT TX from TX interrupt is too long From: sonic zhang To: Alan Cox , Linux Kernel , Linux Serial Content-Type: text/plain Date: Mon, 21 Sep 2009 19:02:53 +0800 Message-ID: <1253530973.22138.16.camel@eight.analog.com> MIME-Version: 1.0 X-Mailer: Evolution 2.8.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1334 Lines: 40 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/