Commit e990e127 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wim Van Sebroeck
Browse files

watchdog: renesas_wdt: don't set divider while watchdog is running 



The datasheet says we must stop the timer before changing the clock
divider. This can happen when the restart handler is called while the
watchdog is running.

Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarFabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent 7db706a2

drivers/watchdog/renesas_wdt.c

+7 −2
Original line number Diff line number Diff line
@@ -74,12 +74,17 @@ static int rwdt_init_timeout(struct watchdog_device *wdev) 
static int rwdt_start(struct watchdog_device *wdev)

{

	struct rwdt_priv *priv = watchdog_get_drvdata(wdev);

	u8 val;



	pm_runtime_get_sync(wdev->parent);



	rwdt_write(priv, 0, RWTCSRB);

	rwdt_write(priv, priv->cks, RWTCSRA);

	/* Stop the timer before we modify any register */

	val = readb_relaxed(priv->base + RWTCSRA) & ~RWTCSRA_TME;

	rwdt_write(priv, val, RWTCSRA);



	rwdt_init_timeout(wdev);

	rwdt_write(priv, priv->cks, RWTCSRA);

	rwdt_write(priv, 0, RWTCSRB);



	while (readb_relaxed(priv->base + RWTCSRA) & RWTCSRA_WRFLG)

		cpu_relax();