From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934068Ab0EUQv7 (ORCPT ); Fri, 21 May 2010 12:51:59 -0400 Received: from kroah.org ([198.145.64.141]:50276 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934030Ab0EUQv4 (ORCPT ); Fri, 21 May 2010 12:51:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Sonic Zhang , Mike Frysinger , Greg Kroah-Hartman Subject: [PATCH 01/25] serial: bfin_sport_uart: work around anomaly 05000473 (make 32bit fifo read atomic) Date: Fri, 21 May 2010 09:51:30 -0700 Message-Id: <1274460714-11277-1-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 We cannot let a 32-bit RX FIFO read be interrupted otherwise a fake RX underflow error might be generated. URL: http://blackfin.uclinux.org/gf/tracker/5145 Signed-off-by: Sonic Zhang Signed-off-by: Mike Frysinger Signed-off-by: Greg Kroah-Hartman --- drivers/serial/bfin_sport_uart.h | 16 +++++++++++++++- 1 files changed, 15 insertions(+), 1 deletions(-) diff --git a/drivers/serial/bfin_sport_uart.h b/drivers/serial/bfin_sport_uart.h index abe0361..9791fcc 100644 --- a/drivers/serial/bfin_sport_uart.h +++ b/drivers/serial/bfin_sport_uart.h @@ -37,7 +37,21 @@ #define SPORT_GET_TFSDIV(sport) bfin_read16(((sport)->port.membase + OFFSET_TFSDIV)) #define SPORT_GET_TX(sport) bfin_read16(((sport)->port.membase + OFFSET_TX)) #define SPORT_GET_RX(sport) bfin_read16(((sport)->port.membase + OFFSET_RX)) -#define SPORT_GET_RX32(sport) bfin_read32(((sport)->port.membase + OFFSET_RX)) +/* + * If another interrupt fires while doing a 32-bit read from RX FIFO, + * a fake RX underflow error will be generated. So disable interrupts + * to prevent interruption while reading the FIFO. + */ +#define SPORT_GET_RX32(sport) \ +({ \ + unsigned int __ret; \ + if (ANOMALY_05000473) \ + local_irq_disable(); \ + __ret = bfin_read32((sport)->port.membase + OFFSET_RX); \ + if (ANOMALY_05000473) \ + local_irq_enable(); \ + __ret; \ +}) #define SPORT_GET_RCR1(sport) bfin_read16(((sport)->port.membase + OFFSET_RCR1)) #define SPORT_GET_RCR2(sport) bfin_read16(((sport)->port.membase + OFFSET_RCR2)) #define SPORT_GET_RCLKDIV(sport) bfin_read16(((sport)->port.membase + OFFSET_RCLKDIV)) -- 1.7.0.3