Thread (32 messages) 32 messages, 4 authors, 2018-08-16

Re: [PATCH v6 10/24] watchdog: jz4740: Avoid starting watchdog in set_timeout

From: Guenter Roeck <linux@roeck-us.net>
Date: 2018-08-10 13:37:39
Also in: linux-clk, linux-devicetree, linux-mips, linux-pwm, linux-watchdog, lkml

On Thu, Aug 09, 2018 at 11:44:00PM +0200, Paul Cercueil wrote:
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@crapouillou.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
quoted hunk ↗ jump to hunk
---
 drivers/watchdog/jz4740_wdt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

 v6: New patch
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
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