diff options
| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2018-11-07 22:46:02 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 21:47:07 +0300 |
| commit | b5bb2cad52643a2b916599891b9bd90f145a1a91 (patch) | |
| tree | 8e5ac066c4841098417008d3b7651b1ea451e8c1 /drivers/watchdog | |
| parent | f06d48b0a4b9edee1f14cce4cbc98eec580d1416 (diff) | |
| download | linux-b5bb2cad52643a2b916599891b9bd90f145a1a91.tar.xz | |
watchdog: renesas_wdt: don't set divider while watchdog is running
[ Upstream commit e990e12741877e9bfac402ca468f4007a75f6e2a ]
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: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/renesas_wdt.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c index 88d81feba4e6..d01efd342dc0 100644 --- a/drivers/watchdog/renesas_wdt.c +++ b/drivers/watchdog/renesas_wdt.c @@ -77,12 +77,17 @@ 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(); |