From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754680Ab0JDJpp (ORCPT ); Mon, 4 Oct 2010 05:45:45 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:59281 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309Ab0JDJpn (ORCPT ); Mon, 4 Oct 2010 05:45:43 -0400 From: vkuzmichev@mvista.com To: linux-arm-kernel@lists.infradead.org Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, linux@arm.linux.org.uk, Vitaly Kuzmichev Subject: [PATCH 1/4] ARM: smp_twd: mpcore_wdt: Fix watchdog counter loading Date: Mon, 4 Oct 2010 13:45:37 +0400 Message-Id: <1286185540-19569-2-git-send-email-vkuzmichev@mvista.com> X-Mailer: git-send-email 1.7.2.2 In-Reply-To: <1286185540-19569-1-git-send-email-vkuzmichev@mvista.com> References: <1286185540-19569-1-git-send-email-vkuzmichev@mvista.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuzmichev Although upstream commit "98af057 ARM: 6126/1: ARM mpcore_wdt: fix build failure and other fixes" resolved long standing mpcore_wdt driver build problems, it introduced an error in the relationship between the MPcore watchdog timer clock rate and mpcore_margin, "MPcore timer margin in seconds", such that watchdog timeouts are now arbitrary rather than the number of seconds specified by mpcore_margin. This change restores mpcore_wdt_keepalive() to its equivalent implementation prior to commit 98af057 such that watchdog timeouts now occur as specified by mpcore_margin. The variable 'mpcore_timer_rate' which caused that build failure was replaced by 'twd_timer_rate'. Adding exported function to obtain twd_timer_rate value in mpcore_wdt driver. A build error will not occur because MPCORE_WATCHDOG needed to build 'mpcore_wdt' depends on HAVE_ARM_TWD needed to build 'smp_twd'. Signed-off-by: Vitaly Kuzmichev --- arch/arm/include/asm/smp_twd.h | 1 + arch/arm/kernel/smp_twd.c | 6 ++++++ drivers/watchdog/mpcore_wdt.c | 11 ++++++++--- 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h index 634f357..c6328d8 100644 --- a/arch/arm/include/asm/smp_twd.h +++ b/arch/arm/include/asm/smp_twd.h @@ -25,5 +25,6 @@ extern void __iomem *twd_base; void twd_timer_stop(void); int twd_timer_ack(void); void twd_timer_setup(struct clock_event_device *); +unsigned long twd_get_timer_rate(void); #endif diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index 35882fb..7bc1173 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -160,3 +160,9 @@ void twd_timer_stop(void) __raw_writel(0, twd_base + TWD_TIMER_CONTROL); } #endif + +unsigned long twd_get_timer_rate(void) +{ + return twd_timer_rate; +} +EXPORT_SYMBOL(twd_get_timer_rate); diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c index b8ec7ac..1bd3529 100644 --- a/drivers/watchdog/mpcore_wdt.c +++ b/drivers/watchdog/mpcore_wdt.c @@ -47,6 +47,11 @@ struct mpcore_wdt { static struct platform_device *mpcore_wdt_dev; static DEFINE_SPINLOCK(wdt_lock); +static unsigned long mpcore_wdt_rate; +module_param_named(rate, mpcore_wdt_rate, ulong, 0); +MODULE_PARM_DESC(rate, + "MPcore watchdog timer rate in Hz. (default=0 - autodetect)"); + #define TIMER_MARGIN 60 static int mpcore_margin = TIMER_MARGIN; module_param(mpcore_margin, int, 0); @@ -99,9 +104,7 @@ static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt) spin_lock(&wdt_lock); /* Assume prescale is set to 256 */ - count = __raw_readl(wdt->base + TWD_WDOG_COUNTER); - count = (0xFFFFFFFFU - count) * (HZ / 5); - count = (count / 256) * mpcore_margin; + count = (mpcore_wdt_rate / 256) * mpcore_margin; /* Reload the counter */ writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD); @@ -434,6 +437,8 @@ static int __init mpcore_wdt_init(void) printk(KERN_INFO "mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n", TIMER_MARGIN); } + if (!mpcore_wdt_rate) + mpcore_wdt_rate = twd_get_timer_rate(); printk(banner, mpcore_noboot, mpcore_margin, nowayout); -- 1.7.2.2