From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pd0-f170.google.com ([209.85.192.170]:54104 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754282AbaIWS14 (ORCPT ); Tue, 23 Sep 2014 14:27:56 -0400 Date: Tue, 23 Sep 2014 11:27:51 -0700 From: Guenter Roeck To: Jisheng Zhang Cc: wim@iguana.be, linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 1/2] watchdog: dw_wdt: initialise TOP_INIT in dw_wdt_set_top() Message-ID: <20140923182751.GA24930@roeck-us.net> References: <1411458132-5410-1-git-send-email-jszhang@marvell.com> <1411458132-5410-2-git-send-email-jszhang@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1411458132-5410-2-git-send-email-jszhang@marvell.com> Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org On Tue, Sep 23, 2014 at 03:42:11PM +0800, Jisheng Zhang wrote: > The TOP_INIT, ie bit 4-7 of the WDOG_TIMEOUT_RANGE_REG_OFFSET register > may be zero, so the timeout period may be very short after initialization > is done, thus the system may be reset soon after enabling. We fix this > problem by also initialising the TOP_INIT when setting TOP in function > dw_wdt_set_top(). > > Signed-off-by: Jisheng Zhang That should do it. Reviewed-by: Guenter Roeck > --- > drivers/watchdog/dw_wdt.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c > index 9f21029..449c885 100644 > --- a/drivers/watchdog/dw_wdt.c > +++ b/drivers/watchdog/dw_wdt.c > @@ -40,6 +40,7 @@ > #define WDOG_CONTROL_REG_OFFSET 0x00 > #define WDOG_CONTROL_REG_WDT_EN_MASK 0x01 > #define WDOG_TIMEOUT_RANGE_REG_OFFSET 0x04 > +#define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT 4 > #define WDOG_CURRENT_COUNT_REG_OFFSET 0x08 > #define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c > #define WDOG_COUNTER_RESTART_KICK_VALUE 0x76 > @@ -106,7 +107,8 @@ static int dw_wdt_set_top(unsigned top_s) > } > > /* Set the new value in the watchdog. */ > - writel(top_val, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); > + writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT, > + dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); > > dw_wdt_set_next_heartbeat(); > > -- > 2.1.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html