Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759765AbYJJKxz (ORCPT ); Fri, 10 Oct 2008 06:53:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759510AbYJJKuq (ORCPT ); Fri, 10 Oct 2008 06:50:46 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:47597 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759482AbYJJKul (ORCPT ); Fri, 10 Oct 2008 06:50:41 -0400 From: Alan Cox Subject: [PATCH 20/27] ip2: avoid add_timer with pending timer To: torvalds@osdl.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Date: Fri, 10 Oct 2008 11:50:37 +0100 Message-ID: <20081010105035.31597.27051.stgit@localhost.localdomain> In-Reply-To: <20081010103447.31597.42992.stgit@localhost.localdomain> References: <20081010103447.31597.42992.stgit@localhost.localdomain> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2500 Lines: 80 From: Akinobu Mita add_timer() is not suppose to be called when the timer is pending. ip2 driver attempts to avoid that condition by setting and resetting a flag (TimerOn) in timer function. But there is some gap between add_timer() and setting TimerOn. This patch fix this problem by using mod_timer() and remove TimerOn which has been unnecessary by this change. Signed-off-by: Akinobu Mita Signed-off-by: Jiri Slaby Signed-off-by: Alan Cox --- drivers/char/ip2/ip2main.c | 19 ++++--------------- 1 files changed, 4 insertions(+), 15 deletions(-) diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c index 39269d1..66f52a2 100644 --- a/drivers/char/ip2/ip2main.c +++ b/drivers/char/ip2/ip2main.c @@ -249,7 +249,6 @@ static unsigned long bh_counter; */ #define POLL_TIMEOUT (jiffies + 1) static DEFINE_TIMER(PollTimer, ip2_poll, 0, 0); -static char TimerOn; #ifdef IP2DEBUG_TRACE /* Trace (debug) buffer data */ @@ -374,11 +373,7 @@ static void __exit ip2_cleanup_module(void) int err; int i; - /* Stop poll timer if we had one. */ - if (TimerOn) { - del_timer(&PollTimer); - TimerOn = 0; - } + del_timer_sync(&PollTimer); /* Reset the boards we have. */ for (i = 0; i < IP2_MAX_BOARDS; i++) @@ -774,10 +769,8 @@ static int __init ip2_loadmain(void) } if (ip2config.irq[i] == CIR_POLL) { retry: - if (!TimerOn) { - PollTimer.expires = POLL_TIMEOUT; - add_timer(&PollTimer); - TimerOn = 1; + if (!timer_pending(&PollTimer)) { + mod_timer(&PollTimer, POLL_TIMEOUT); printk(KERN_INFO "IP2: polling\n"); } } else { @@ -1283,16 +1276,12 @@ ip2_poll(unsigned long arg) { ip2trace (ITRC_NO_PORT, ITRC_INTR, 100, 0 ); - TimerOn = 0; // it's the truth but not checked in service - // Just polled boards, IRQ = 0 will hit all non-interrupt boards. // It will NOT poll boards handled by hard interrupts. // The issue of queued BH interrupts is handled in ip2_interrupt(). ip2_polled_interrupt(); - PollTimer.expires = POLL_TIMEOUT; - add_timer( &PollTimer ); - TimerOn = 1; + mod_timer(&PollTimer, POLL_TIMEOUT); ip2trace (ITRC_NO_PORT, ITRC_INTR, ITRC_RETURN, 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/