From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jun Chen Subject: [PATCH] serial: ifx6x60: add_timer is not safe in the mrdy_assert function Date: Mon, 22 Oct 2012 10:23:07 -0400 Message-ID: <1350915787.4332.27.camel@chenjun-workstation> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com ([134.134.136.24]:20994 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752784Ab2JVGUr (ORCPT ); Mon, 22 Oct 2012 02:20:47 -0400 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: alan@linux.intel.com Cc: linux-serial@vger.kernel.org, russ.gorby@intel.com, chuansheng.liu@intel.com, chao.bi@intel.com This patch make use of mod_timer instead of add_timer in the mrdy_assert function. Because the srdy interrupter can go high when we are running function mrdy_assert and mrdy_assert can be called by multi-entry. In our medfield platform, spi stress test can encounter this error logs triggered by the BUG_ON of add_timer function.This patch had been tested on our medfield platform. the scenario: CPU0 CPU1 mrdy_assert set_bit(IFX_SPI_STATE_TIMER_PENDING) ifx_spi_handle_srdy ... clear_bit(IFX_SPI_STATE_TIMER_PENDING) ... mrdy_assert set_bit(IFX_SPI_STATE_TIMER_PENDING) ... add_timer ... add_timer cc:liu chuansheng cc:Bi Chao Signed-off-by: Chen Jun --- drivers/tty/serial/ifx6x60.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c index 769396a..e56ed33 100644 --- a/drivers/tty/serial/ifx6x60.c +++ b/drivers/tty/serial/ifx6x60.c @@ -190,9 +190,7 @@ static void mrdy_assert(struct ifx_spi_device *ifx_dev) if (!val) { if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) { - ifx_dev->spi_timer.expires = - jiffies + IFX_SPI_TIMEOUT_SEC*HZ; - add_timer(&ifx_dev->spi_timer); + mod_timer(&ifx_dev->spi_timer,jiffies + IFX_SPI_TIMEOUT_SEC*HZ); } } -- 1.7.4.1