linux-kernel - [PATCH v11 09/27] watchdog: jz4740: Avoid starting watchdog in set

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190327231631.15708-10-paul@crapouillou.net>
Date:   Thu, 28 Mar 2019 00:16:13 +0100
From:   Paul Cercueil <paul@...pouillou.net>
To:     Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Thierry Reding <thierry.reding@...il.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Ralf Baechle <ralf@...ux-mips.org>,
        Paul Burton <paul.burton@...s.com>,
        James Hogan <jhogan@...nel.org>,
        Jonathan Corbet <corbet@....net>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     Mathieu Malaterre <malat@...ian.org>, od@...c.me,
        linux-pwm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-watchdog@...r.kernel.org,
        linux-mips@...r.kernel.org, linux-doc@...r.kernel.org,
        linux-clk@...r.kernel.org, Paul Cercueil <paul@...pouillou.net>
Subject: [PATCH v11 09/27] watchdog: jz4740: Avoid starting watchdog in set_timeout

Previously the jz4740_wdt_set_timeout() function was starting the timer
unconditionally, even if it was stopped when that function was entered.

Now, the timer will be restarted only if it was already running before
this function is called.

Signed-off-by: Paul Cercueil <paul@...pouillou.net>
Reviewed-by: Guenter Roeck <linux@...ck-us.net>
Tested-by: Mathieu Malaterre <malat@...ian.org>
Tested-by: Artur Rojek <contact@...ur-rojek.eu>
---
 drivers/watchdog/jz4740_wdt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
index 0f54306aee25..45d9495170e5 100644
--- a/drivers/watchdog/jz4740_wdt.c
+++ b/drivers/watchdog/jz4740_wdt.c
@@ -64,13 +64,15 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
 {
 	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
 	u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout);
+	u32 tcer;
 
+	regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
 	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
 
 	regmap_write(drvdata->map, TCU_REG_WDT_TDR, timeout_value);
 	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
 
-	regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
+	regmap_write(drvdata->map, TCU_REG_WDT_TCER, tcer & TCU_WDT_TCER_TCEN);
 
 	wdt_dev->timeout = new_timeout;
 	return 0;
@@ -86,6 +88,7 @@ static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
 		return ret;
 
 	jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
+	regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
 
 	return 0;
 }
-- 
2.11.0