Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965350AbdIZGMJ (ORCPT ); Tue, 26 Sep 2017 02:12:09 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:47691 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965297AbdIZGMH (ORCPT ); Tue, 26 Sep 2017 02:12:07 -0400 From: Oleksij Rempel To: Wim Van Sebroeck , Guenter Roeck , Dinh Nguyen , Rob Herring , Mark Rutland Cc: Oleksij Rempel , linux-watchdog@vger.kernel.org, kernel@pengutronix.de, Russell King , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/2] watchdog: dw_wdt: add stop watchdog operation Date: Tue, 26 Sep 2017 08:11:22 +0200 Message-Id: <20170926061123.29614-1-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.11.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2096 Lines: 74 The only way of stopping the watchdog is by resetting it. Add the watchdog op for stopping the device and reset if a reset line is provided. At same time WDOG_HW_RUNNING should be remove from dw_wdt_start. As commented by Guenter Roeck: dw_wdt sets WDOG_HW_RUNNING in its open function. Result is that the kref_get() in watchdog_open() won't be executed. But then kref_put() in close will be called since the watchdog now does stop. This causes the imbalance. Signed-off-by: Oleksij Rempel Cc: Wim Van Sebroeck Cc: Guenter Roeck Cc: linux-watchdog@vger.kernel.org --- changes v4: - remove WDOG_HW_RUNNING from dw_wdt_start. changes v3: - don't return error if rst is not present and set WDOG_HW_RUNNING bit to notify watchdog core. changes v2: - test if dw_wdt->rst is NULL instead of IS_ERR drivers/watchdog/dw_wdt.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 36be987ff9ef..c2f4ff516230 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -127,14 +127,27 @@ static int dw_wdt_start(struct watchdog_device *wdd) dw_wdt_set_timeout(wdd, wdd->timeout); - set_bit(WDOG_HW_RUNNING, &wdd->status); - writel(WDOG_CONTROL_REG_WDT_EN_MASK, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); return 0; } +static int dw_wdt_stop(struct watchdog_device *wdd) +{ + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); + + if (!dw_wdt->rst) { + set_bit(WDOG_HW_RUNNING, &wdd->status); + return 0; + } + + reset_control_assert(dw_wdt->rst); + reset_control_deassert(dw_wdt->rst); + + return 0; +} + static int dw_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { @@ -173,6 +186,7 @@ static const struct watchdog_info dw_wdt_ident = { static const struct watchdog_ops dw_wdt_ops = { .owner = THIS_MODULE, .start = dw_wdt_start, + .stop = dw_wdt_stop, .ping = dw_wdt_ping, .set_timeout = dw_wdt_set_timeout, .get_timeleft = dw_wdt_get_timeleft, -- 2.11.0