From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-cys01nam02hn0235.outbound.protection.outlook.com ([104.47.37.235]:46756 "EHLO NAM02-CY1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933337AbeCSPr3 (ORCPT ); Mon, 19 Mar 2018 11:47:29 -0400 From: Sasha Levin To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" CC: Oleksij Rempel , Wim Van Sebroeck , Guenter Roeck , "linux-watchdog@vger.kernel.org" , Sasha Levin Subject: [PATCH AUTOSEL for 4.15 022/124] watchdog: dw_wdt: add stop watchdog operation Date: Mon, 19 Mar 2018 15:47:21 +0000 Message-ID: <20180319154645.11350-22-alexander.levin@microsoft.com> References: <20180319154645.11350-1-alexander.levin@microsoft.com> In-Reply-To: <20180319154645.11350-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: Oleksij Rempel [ Upstream commit 1bfe8889380890efe4943d125124f5a7b48571b0 ] 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 Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- 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) =20 dw_wdt_set_timeout(wdd, wdd->timeout); =20 - set_bit(WDOG_HW_RUNNING, &wdd->status); - writel(WDOG_CONTROL_REG_WDT_EN_MASK, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); =20 return 0; } =20 +static int dw_wdt_stop(struct watchdog_device *wdd) +{ + struct dw_wdt *dw_wdt =3D 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 =3D { static const struct watchdog_ops dw_wdt_ops =3D { .owner =3D THIS_MODULE, .start =3D dw_wdt_start, + .stop =3D dw_wdt_stop, .ping =3D dw_wdt_ping, .set_timeout =3D dw_wdt_set_timeout, .get_timeleft =3D dw_wdt_get_timeleft, --=20 2.14.1