From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934076Ab0EUQwD (ORCPT ); Fri, 21 May 2010 12:52:03 -0400 Received: from kroah.org ([198.145.64.141]:50281 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934054Ab0EUQv5 (ORCPT ); Fri, 21 May 2010 12:51:57 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Sonic Zhang , Mike Frysinger , Greg Kroah-Hartman Subject: [PATCH 02/25] serial: bfin_sport_uart: shorten the SPORT TX waiting loop Date: Fri, 21 May 2010 09:51:31 -0700 Message-Id: <1274460714-11277-2-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.7.0.3 In-Reply-To: <20100521165113.GB11216@kroah.com> References: <20100521165113.GB11216@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sonic Zhang 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 files changed, 7 insertions(+), 1 deletions(-) diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c index c88f8ad..6991c36 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; } -- 1.7.0.3