From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleksij Rempel , Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org, Sasha Levin Subject: [PATCH 4.14 019/138] watchdog: dw_wdt: add stop watchdog operation Date: Wed, 11 Apr 2018 00:23:29 +0200 Message-Id: <20180410212904.317032823@linuxfoundation.org> In-Reply-To: <20180410212902.121524696@linuxfoundation.org> References: <20180410212902.121524696@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 List-Archive: List-Post: List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/watchdog/dw_wdt.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -127,14 +127,27 @@ static int dw_wdt_start(struct watchdog_ 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 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,